User blog comment:Harbumz/Introducing Vignette, Wikia's New Thumbnailer/@comment-3495717-20150212131246/@comment-76.14.56.173-20150212155704

We've noticed that some gifs have that artifacting issue when they're thumbnailed. The old thumbnailer avoided this by thumbnailing a frame (first I think) in the image, but Vignette plays the gif animations.