The artist has shared two iterations of their painting, and you can flick through their post history to see them honing their skills over five years, including more art on the same clothed-mice theme, also with multiple versions.
~~Using an AI tool uncritically on !fuck_ai@lemmy.world to accuse a genuine artist of using AI is not really in the spirit of the community, IMO.~~ Edit: miscommunication -- OP was spotlighting the mistake made by the detection tool, not accusing the artist of using AI.