Video on Lemmy is still a pain.
GIF is an old standard that new developers want to get rid of but can't for all kinds of reasons ... WEBM and MP4 is far better but services won't, can't or don't follow standards at all ... Imgur is one where you can load a WEBM and it will called a GIF ... or load a GIF and it will be converted to a GIF ... but then all the different Lemmy apps, sites and services all get confused because everyone everywhere keep mixing up GIF quality, format, size and delivery and in calling video files GIF that aren't GIF ... GIF is also a very inefficient format which creates huge file sizes, so few places want to host them, so you end up with services like catbox, which take a lot of load time to play and usually send you to two or three clicks before you can play the video or GIF at all ... it all just means that creating, loading, serving and hosting a GIF and expecting it to play on Lemmy is still a lottery