post #7053286 (look at her left ear and check other works from this artist). So, it's some kind of intentional artifact that the author introduces to his images to disturb AI when it's learning.
We already have a regular watermark tag, but I don't think it should be used for such things. Can we invent a new tag? Maybe anti-ai-watermark or anti-ai-artifact? Maybe there is already some tag for it and I just don't know.