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

Is this the reason why animated .gifs with background transparency don't display correctly when used in galleries or when downscaled?

When I say that they don't display correctly, I mean that the background of the .gif flashes between transparent and pure white, sometimes leaving behind traces of previous frames of the animation.