Bluesky's video compression starts when the video starts but it switches to a higher resolution around a third-ish way through, i discovered this through a trial and error of trying to figure out why my looping animation was so low quality. I hope this helps in understanding it.

That's silly. It's also silly that the sound can de-sync from the video, as I just discovered. I went back and watched the original file, because I started to wonder how I missed it. But that's definitely in sync. I'm sure the player will improve eventually, but these little things are so weird.