As the title says. I have an animation I would like to upload but it's a gif taken from a flash, not sure if that counts as a screenshot.

I think when they say screenshots they mean stuff from Second Life or something like that. As long as the admins deem it "Fap worthy" I think it should be fine.

I presume that e621 has no screenshots rule for the same reason as the other boards: because without it, users tend to upload low effort frame-by-frame screencaps by thousands. R34 in particular had a major problem with that, before the wipe. Skyrim mods, Mass Effect sex scenes, Second Life, etc...

I don't think that animations fall in the same category, but I might be wrong.

It's a quality thing. It mostly targets Garry's Mod, popular games (like Skyrim), and SL type games where you 'screenshot' it and upload it here.

We want e621 to be a repository of decent quality art and a screenshot takes away from legitimate art.

Hope this helps!