As someone who considers himself a relatively informed netizen, I hadn't even heard of e621.net until now, and I don't know whether I should be proud or ashamed of that.
There's in fact a Stable Diffusion model trained on most of e621. Uh not sure what HN's linking rules are, but look up Furtastic.
Though I understand and respect furrydom, I'm not a furry... But in its niche of generating anthropomorphic people, I still find the model to be incredible. Its got to be one of the most extensively trained, tagged and coherent SD 1.5 finetunes out there, which doesn't even surprise me TBH.
I'm not usually impressed by generated images. But the furry models are astounding. Right now my best signal for something being AI is that it's incredibly detailed by doesn't have a signature.
As a seperate note, I saw another HNer blog post specifically complain about AI generated furry art as a destroyer of talented furry artists... I get the point, but still have mixed feelings.
If some AI is so incredible at an artistic niche (not just furry), isn't that amazing? If artists are not economically free to pursue new styles and representations the AI doesn't "know," I feel thats a larger problem with society and art platforms, not AI specifically.
I mean only if you care about furries, for anime Danbooru is probably an equivalent, funny enough I have never found a website like E621 and Danbooru with real photos, the tagging is always terrible.
(Edit: Apparently there's a sister site called E926 to share SFW content. E926 is yet another food additive (Chlorine Dioxide) which is used to bleach food for a cleaner appearance.)