My limited understanding is that there's an association between the shark's colors and the trans flag, and that this predates that instance in the trans world.
Honestly, I don't even care if people want to run a censored instance -- like, some people legitimately do not want to see some content -- but I do think that they should be clear that they are doing so, which it sounds like they were not in this case.
Also does make one wonder whether other material might be missing on other topics from other communities.
ponders
As a general solution to making instance censorship visible, I suppose that it'd be technically-possible to write a bot that could spider Threadiverse instances and look for discrepancies between views of a community, provide a summary of instance censorship activity. If an admin wanted to silently censor content and wanted to go to enough work to make the censorship silent, they could try to identify the bot and only show posts to it, but I imagine that it'd be more work, especially if it acted anonymously and from a VPN.
As a bonus, that could also flag post propagation problems of the sort I mentioned elsewhere in this thread, kind of be a "Threadiverse health monitor".
Lemmy.dbzer0.com has a community aimed at highlighting this sort of thing, !yepowertrippinbastards@lemmy.dbzer0.com.
I'm personally not sure that it's actually a great way to deal with unreasonable mod or admin actions -- I'd favor general technical solutions like the spider I mentioned in this thread over having "name and shame" stuff where possible, think that name-and-shame tends to generate conflict. But I suppose that it does help people who might object to such actions, like lemmy.blahaj.zone home instance users in this case, be aware that they are getting a censored view and choose communities and instances accordingly. I mean, I'd want to know myself if my own home instance admin were silently removing content on my instance.