What kind of artifacting is going on in this image? I've seen it show up in a few other uploads lately (can't remember which), and it reminds me of patterns I recall seeing in early images produced by neural networks ...

I read where this is the effect from anti-AI software such as Nightshade or Glaze that prevents AI scraping.

The current tag for this is adversarial noise. It used to be glaze artifacts but there are now several ways to create these patterns like Nightshade as mentioned above.
Clip Studio Paint now has support to create these patterns as well, so these artifacts will become more common as time goes on.