Requested feature overview description.

Any kind of indicator for animated posts on the thumbnail. A Small camera icon placed on the corner of the thumbnail would be nice.

Why would it be useful?

It would be useful for telling what post is animated without clicking it.

What part(s) of the site page(s) are affected?

Any pages that contain animated posts.

You can sorta do this already by placing your cursor over the post and looking for the word animated in the tag lists that pops up. A clearly visible icon in the corner or something would be a better option because it would be easier to tell and not all users have access to a cursor.