diff --git a/frontend/src/components/gallery/layouts/CarouselGalleryLayout.tsx b/frontend/src/components/gallery/layouts/CarouselGalleryLayout.tsx
index f20d040e..14a3360b 100644
--- a/frontend/src/components/gallery/layouts/CarouselGalleryLayout.tsx
+++ b/frontend/src/components/gallery/layouts/CarouselGalleryLayout.tsx
@@ -158,7 +158,13 @@ export const CarouselGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
                     } catch {
                       return;
                     }
-                    setLikedIds(prev => new Set(prev).add(currentPhoto.id));
+                    // Toggle — server /feedback like is a toggle (#590).
+                    setLikedIds(prev => {
+                      const next = new Set(prev);
+                      if (next.has(currentPhoto.id)) next.delete(currentPhoto.id);
+                      else next.add(currentPhoto.id);
+                      return next;
+                    });
                     try {
                       await feedbackService.submitFeedback(slug!, String(currentPhoto.id), {
                         feedback_type: 'like',
@@ -171,7 +177,13 @@ export const CarouselGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
                     setShowIdentityModal(true);
                     return;
                   }
-                  setLikedIds(prev => new Set(prev).add(currentPhoto.id));
+                  // Toggle — server /feedback like is a toggle (#590).
+                  setLikedIds(prev => {
+                    const next = new Set(prev);
+                    if (next.has(currentPhoto.id)) next.delete(currentPhoto.id);
+                    else next.add(currentPhoto.id);
+                    return next;
+                  });
                   try {
                     await feedbackService.submitFeedback(slug!, String(currentPhoto.id), {
                       feedback_type: 'like',
diff --git a/frontend/src/components/gallery/layouts/GalleryPremiumLayout.tsx b/frontend/src/components/gallery/layouts/GalleryPremiumLayout.tsx
index 9bc02f12..1cd4ef23 100644
--- a/frontend/src/components/gallery/layouts/GalleryPremiumLayout.tsx
+++ b/frontend/src/components/gallery/layouts/GalleryPremiumLayout.tsx
@@ -260,9 +260,11 @@ export const GalleryPremiumLayout: React.FC<GalleryPremiumLayoutProps> = ({
       } catch {
         return;
       }
+      // Toggle — server /feedback like is a toggle (#590).
       setLikedPhotoIds(prev => {
         const next = new Set(prev);
-        next.add(photo.id);
+        if (next.has(photo.id)) next.delete(photo.id);
+        else next.add(photo.id);
         return next;
       });
       try {
@@ -282,10 +284,11 @@ export const GalleryPremiumLayout: React.FC<GalleryPremiumLayoutProps> = ({
       return;
     }
 
-    // Optimistic update
+    // Optimistic update — toggle, not add (#590).
     setLikedPhotoIds(prev => {
       const next = new Set(prev);
-      next.add(photo.id);
+      if (next.has(photo.id)) next.delete(photo.id);
+      else next.add(photo.id);
       return next;
     });
 
@@ -306,9 +309,14 @@ export const GalleryPremiumLayout: React.FC<GalleryPremiumLayoutProps> = ({
     setShowIdentityModal(false);
 
     if (pendingLikePhotoId) {
+      // Toggle — server /feedback like is a toggle (#590). The identity
+      // modal only fires the first time per session, so the user is
+      // intentionally liking a not-yet-liked photo here, but keep the
+      // setter shape consistent with the other paths.
       setLikedPhotoIds(prev => {
         const next = new Set(prev);
-        next.add(pendingLikePhotoId);
+        if (next.has(pendingLikePhotoId)) next.delete(pendingLikePhotoId);
+        else next.add(pendingLikePhotoId);
         return next;
       });
 
diff --git a/frontend/src/components/gallery/layouts/GridGalleryLayout.tsx b/frontend/src/components/gallery/layouts/GridGalleryLayout.tsx
index 4a89c1f2..2bbff5a8 100644
--- a/frontend/src/components/gallery/layouts/GridGalleryLayout.tsx
+++ b/frontend/src/components/gallery/layouts/GridGalleryLayout.tsx
@@ -443,9 +443,12 @@ export const GridGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
               onFeedbackChange={onFeedbackChange}
               liked={likedPhotoIds.has(photo.id)}
               onLikeSuccess={() => {
+                // Toggle, not add — like endpoint toggles server-side,
+                // so the optimistic UI has to follow suit on click 2 (#590).
                 setLikedPhotoIds((prev) => {
                   const next = new Set(prev);
-                  next.add(photo.id);
+                  if (next.has(photo.id)) next.delete(photo.id);
+                  else next.add(photo.id);
                   return next;
                 });
               }}
@@ -482,11 +485,12 @@ export const GridGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
               guest_name: name,
               guest_email: email,
             });
-            // Immediately reflect like UI
+            // Immediately reflect like UI — toggle for consistency (#590).
             if (pendingAction.type === 'like') {
               setLikedPhotoIds((prev) => {
                 const next = new Set(prev);
-                next.add(pendingAction.photoId);
+                if (next.has(pendingAction.photoId)) next.delete(pendingAction.photoId);
+                else next.add(pendingAction.photoId);
                 return next;
               });
             }
diff --git a/frontend/src/components/gallery/layouts/JustifiedGalleryLayout.tsx b/frontend/src/components/gallery/layouts/JustifiedGalleryLayout.tsx
index f34d4f36..00b26ccb 100644
--- a/frontend/src/components/gallery/layouts/JustifiedGalleryLayout.tsx
+++ b/frontend/src/components/gallery/layouts/JustifiedGalleryLayout.tsx
@@ -763,9 +763,12 @@ export const JustifiedGalleryLayout: React.FC<JustifiedGalleryLayoutProps> = ({
               onFeedbackChange={onFeedbackChange}
               liked={likedPhotoIds.has(photo.id)}
               onLikeSuccess={() => {
+                // Toggle, not add — like endpoint toggles server-side,
+                // so the optimistic UI has to follow suit on click 2 (#590).
                 setLikedPhotoIds((prev) => {
                   const next = new Set(prev);
-                  next.add(photo.id);
+                  if (next.has(photo.id)) next.delete(photo.id);
+                  else next.add(photo.id);
                   return next;
                 });
               }}
@@ -788,10 +791,12 @@ export const JustifiedGalleryLayout: React.FC<JustifiedGalleryLayoutProps> = ({
                 guest_name: name,
                 guest_email: email,
               });
+              // Toggle for consistency (#590).
               if (pendingAction.type === 'like') {
                 setLikedPhotoIds((prev) => {
                   const next = new Set(prev);
-                  next.add(pendingAction.photoId);
+                  if (next.has(pendingAction.photoId)) next.delete(pendingAction.photoId);
+                  else next.add(pendingAction.photoId);
                   return next;
                 });
               }
diff --git a/frontend/src/components/gallery/layouts/MasonryGalleryLayout.tsx b/frontend/src/components/gallery/layouts/MasonryGalleryLayout.tsx
index 9cd5b0db..bad05802 100644
--- a/frontend/src/components/gallery/layouts/MasonryGalleryLayout.tsx
+++ b/frontend/src/components/gallery/layouts/MasonryGalleryLayout.tsx
@@ -832,9 +832,13 @@ export const MasonryGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
                 columnWidth={columnWidth}
                 liked={likedPhotoIds.has(photo.id)}
                 onLikeSuccess={() => {
+                  // Toggle, not add — the /feedback like endpoint toggles
+                  // server-side, so click 2 on a liked photo unlikes it;
+                  // the optimistic UI must follow suit (#590).
                   setLikedPhotoIds((prev) => {
                     const next = new Set(prev);
-                    next.add(photo.id);
+                    if (next.has(photo.id)) next.delete(photo.id);
+                    else next.add(photo.id);
                     return next;
                   });
                 }}
diff --git a/frontend/src/components/gallery/layouts/MosaicGalleryLayout.tsx b/frontend/src/components/gallery/layouts/MosaicGalleryLayout.tsx
index 2335afe2..c47643b1 100644
--- a/frontend/src/components/gallery/layouts/MosaicGalleryLayout.tsx
+++ b/frontend/src/components/gallery/layouts/MosaicGalleryLayout.tsx
@@ -116,7 +116,8 @@ const MosaicPhoto: React.FC<MosaicPhotoProps> = ({
                       } catch {
                         return;
                       }
-                      setLikedLocal(true);
+                      // Toggle — server /feedback like is a toggle (#590).
+                      setLikedLocal(prev => !prev);
                       try {
                         await feedbackService.submitFeedback(slug!, String(photo.id), {
                           feedback_type: 'like',
@@ -129,7 +130,8 @@ const MosaicPhoto: React.FC<MosaicPhotoProps> = ({
                       setShowIdentityModal(true);
                       return;
                     }
-                    setLikedLocal(true);
+                    // Toggle — server /feedback like is a toggle (#590).
+                    setLikedLocal(prev => !prev);
                     try {
                       await feedbackService.submitFeedback(slug!, String(photo.id), {
                         feedback_type: 'like',
diff --git a/frontend/src/components/gallery/layouts/TimelineGalleryLayout.tsx b/frontend/src/components/gallery/layouts/TimelineGalleryLayout.tsx
index 279fdbb7..de3a7ddd 100644
--- a/frontend/src/components/gallery/layouts/TimelineGalleryLayout.tsx
+++ b/frontend/src/components/gallery/layouts/TimelineGalleryLayout.tsx
@@ -155,7 +155,13 @@ export const TimelineGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
                                   } catch {
                                     return;
                                   }
-                                  setLikedIds(prev => new Set(prev).add(photo.id));
+                                  // Toggle — server /feedback like is a toggle (#590).
+                                  setLikedIds(prev => {
+                                    const next = new Set(prev);
+                                    if (next.has(photo.id)) next.delete(photo.id);
+                                    else next.add(photo.id);
+                                    return next;
+                                  });
                                   try {
                                     await feedbackService.submitFeedback(slug!, String(photo.id), {
                                       feedback_type: 'like',
@@ -168,7 +174,13 @@ export const TimelineGalleryLayout: React.FC<BaseGalleryLayoutProps> = ({
                                   setShowIdentityModal(true);
                                   return;
                                 }
-                                setLikedIds(prev => new Set(prev).add(photo.id));
+                                // Toggle — server /feedback like is a toggle (#590).
+                                setLikedIds(prev => {
+                                  const next = new Set(prev);
+                                  if (next.has(photo.id)) next.delete(photo.id);
+                                  else next.add(photo.id);
+                                  return next;
+                                });
                                 try {
                                   await feedbackService.submitFeedback(slug!, String(photo.id), {
                                     feedback_type: 'like',