How does #Mastodon decide if a video is a "GIF" or of it's a proper video? I keep coming across the GIF for short videos but I don't know what triggers it as all the videos I upload are from the same source.

It's also funny how the meaning of "GIF" was lost over time when it now seems to mean "a short video" and not the originally only universally supported animated standard image format that once littered the web in banners and button graphics.