Transition back, with a tiny bounce

wagtail/wagtailadmin/static_src/wagtailadmin/scss/core.scss

@@ -385,11 +385,11 @@ footer,
             float: none;
             margin: auto;
             display: block;
+            transition: all 0.25s cubic-bezier(0.28, 0.15, 0, 2.1);
         }
 
         img:hover {
             transform: rotate(4deg);
-            transition: all 0.1s ease-in-out 0.1s;
         }
     }