Guys i'm pretty sure this dose not work no more... First go to this website: https://worldlanguages.github.io/animatedThumbnailsBookmarklet/ Then add that website as a bookmark. After that go to the project you want the gif thumbnail in then click the bookmark and finely select the picture you want from your downloads. And There It Have A Gif Thumbnail!
all by me.. if you need help just comment.
