"Crappy Design" as in I can't view the video?
No video with supported format and MIME type found.
I think that's the fault of whatever app / frontend you are using. On OP's instance (which is just rendering HTML), and on the community's instance (using lemmy-ui), this file plays. In both cases, it's a bog-standard MP4 inside a VIDEO tag with a video/mp4 type. If - for example - you're using Sync, then that app also can't play MP4s hosted by Mastodon either.
Checked with your instance (feddit.nl), community's instance (sh.itjust.works), and with lemmy.world. None show a thumbnail, but all can play the video (at least on default interface).
Indeed, for some reason, the video cannot be viewed when opened in another browser tab
Ok, but can you pull it?
