My guy, expect to see shit when in a shitposting community, that’s the whole point. If you don’t like shitposts (not sure why you are saying it isn’t a shitpost, it’s literally a perfect example of one) then block the community and save yourself some cycles.

I am selfhosting! And yeah, I actually forgot there was a theme on the phone/messaging/camera apps, the theme just came with the OS and I haven’t bothered changing anything. The browser isn’t themed, it’s just the GrapheneOS browser Vanadium.