Change embedded posts to use web UI (#31766)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/mastodon/components/logo.tsx

@@ -7,6 +7,13 @@ export const WordmarkLogo: React.FC = () => (
   </svg>
 );
 
+export const IconLogo: React.FC = () => (
+  <svg viewBox='0 0 79 79' className='logo logo--icon' role='img'>
+    <title>Mastodon</title>
+    <use xlinkHref='#logo-symbol-icon' />
+  </svg>
+);
+
 export const SymbolLogo: React.FC = () => (
   <img src={logo} alt='Mastodon' className='logo logo--icon' />
 );