[quote=Neobullseye]
So, wait. Since when are PG files animation-compatible? I thought that that was limited to GIF files O_oEDIT: Explanation attempt no.1: Maybe it's actually a GIF.file renamed as a JPG one? It's still a GIF for all intents and purposes, it's just not called that anymore.
[/quote]

Re-rendering a gif as a jpg would cause it to de-animate and act like a normal jpg. (And if it wasn't re-rendered, then the file would become corrupted and not display an image.)