diff --git a/api/router.ts b/api/router.ts
index 3ca0b6c..d0e0ef8 100644
--- a/api/router.ts
+++ b/api/router.ts
@@ -7,7 +7,7 @@ import { readWebsiteStatus, cloneWebsite, updateWebsite } from './website';
 import { readMediaStatus, createMediaDir } from './media';
 import { readSync, startSync } from './sync';
 import { readRuns } from './ledger';
-import { reconcile } from './derive';
+import { listOriginals, originalsDir, reconcile, safeScope } from './derive';
 import { createDatabases, pushSchema, readDatabases } from './databases';
 import { readBackups, restoreBackup, runBackup, saveBackups, schedule, testDestination } from './backups';
 import { watchMailbox } from './messages';
@@ -250,6 +250,30 @@ router.post('/_config/media/create', async (ctx) => {
  * "Already running" is not a failure to report to somebody who pressed Sync; the honest answer is the
  * run that is in progress, which is what comes back.
  */
+/**
+ * The media files under a folder in `originals/`, relative to it.
+ *
+ * For "Create Gallery" on a directory: what somebody right-clicked is the folder, and what a gallery
+ * holds is the files. Expanded here rather than in the browser because this side already knows which
+ * extensions are media and how to walk the tree — `listOriginals` is the same function the sync uses,
+ * so a gallery cannot contain a file the pipeline would not convert.
+ *
+ * Recursive, deliberately: a folder of folders is still "these pictures", and refusing to descend would
+ * make the action silently miss most of what somebody pointed at.
+ */
+router.get('/_config/media/files', async (ctx) => {
+  const user = ctx.get('user');
+  const scope = ctx.req.query('path') ?? '';
+  try {
+    const root = await originalsDir(user.email);
+    const files = await listOriginals(root, safeScope(scope));
+    // Prefixed back to the scope, so what comes out is what a gallery item stores.
+    return ctx.json({ files: files.map((file) => (scope ? `${safeScope(scope)}/${file}` : file)) });
+  } catch (error) {
+    return ctx.json({ error: (error as Error).message }, 400);
+  }
+});
+
 router.post('/_config/media/sync', async (ctx) => {
   const user = ctx.get('user');
   // A folder inside `originals/`, or nothing for all of it. Named `path` because that is what the file
diff --git a/web/file-actions.ts b/web/file-actions.ts
index b49e3cc..39b3d0d 100644
--- a/web/file-actions.ts
+++ b/web/file-actions.ts
@@ -43,8 +43,32 @@ export const fileActions: FileAction[] = [
       const directories = entries.filter((entry) => entry.type === 'directory').length;
       return directories === 0 || (directories === 1 && entries.length === 1);
     },
-    run: (entries) => {
-      const paths = entries.map((entry) => relativeTo(entry.path)).filter((path): path is string => Boolean(path));
+    run: async (entries) => {
+      /*
+        A folder is expanded into the files inside it.
+
+        What somebody right-clicked is the directory; what a gallery holds is pictures. Without this the
+        gallery gets one item — the folder — which is what shipped first and is obviously wrong the
+        moment you look at it.
+
+        Expanded by the SERVER, because that side already knows which extensions are media and how to
+        walk the tree: it is the same `listOriginals` the sync uses, so a gallery cannot end up holding
+        a file the pipeline would never convert.
+      */
+      const chosen = entries.map((entry) => relativeTo(entry.path)).filter((path): path is string => Boolean(path));
+
+      let paths = chosen;
+      if (entries.length === 1 && entries[0]!.type === 'directory') {
+        const response = await fetch(
+          `/api/fofos-admin/_config/media/files?path=${encodeURIComponent(chosen[0] ?? '')}`,
+          { credentials: 'same-origin' },
+        ).catch(() => null);
+
+        const body = response?.ok ? ((await response.json()) as { files?: string[] }) : null;
+        // Falling back to the folder itself would create the wrong gallery quietly. Nothing is better.
+        if (!body?.files?.length) return;
+        paths = body.files;
+      }
       /*
         Handed over in the URL, and the Galleries panel does the asking.