Maybe the author's friend is just way better than me at this, but I tried applying her advice to some of the other images and I don't feel like it would have helped me.

Looking at the human impressionist painting "Entrance to the Village of Osny" that lots of people (including me) thought was AI, it seems like there's lots of details which don't really make sense. The road seems to seamlessly become the wall of a house on the right side for instance. On the other hand, even looking at the details, there's no details in the cherub image that I could see which would give anything away.

It’s impressionist. It’s not supposed to make sense in the sense that it’s an accurate reflection of reality; it’s supposed to make sense in that you can understand why the details were drawn in the way they were because someone put thought and intention into them.

I was able to tell because the distant houses are placed in a nonsensical formation in the AI image, but in the human image they make sense (they're more of a 'swoosh').

The arms look, er, not very feminine.