Case in point right now "sensory block pit trap" seems to be doing the rounds, a while ago it was "personality excretion as coloured jelly" and before that some less extreme ones such as "the jack-o pose" and "Sailor Moon redraw". Now obviously any of these will be someone's fetish but I'm not asking why they exist at all. Rather, there seem to be distinctive short-lived trends primarily in the Japanese art sphere (mostly seen on Pixiv and Twitter in my case) where many artists are drawing one or two works matching a specific obscure pattern and then no more, so they're not just intensely into it. So, where do they come from? How do they get started? Is there one big artist imageboard where these things go viral like reddit's default ranking? Are there a bunch of whales who get an itch and commission a bunch of artists at the same time? Big popular/influential artists leading the pack? Just a glitch in social media algorithms?