A friend had the brilliant idea of asking one of those image AIs to draw a diagram of the anatomy of a human hand, since that seems to be the thing they have the most trouble drawing. The AI managed then produced these diagrams, which are frankly impressive in some ways, while 100 % confirming that they cannot draw human hands. Never mind getting the number of fingers right, look at these skeletal structures and tell me there aren't deeper issues at work.
It's because the difficulty of highly detailed illustrations lies in the mechanical aspects that stand in between the idea of the thing in one's brain and the abstraction of that on the paper/tablet/whatever medium. For these AIs, there's no idea of the thing or messy systems of tendons and muscles getting in the way, there's just a feverish image formed through data association.
The real breakthrough I think would by layering the system with something that could create that sort of idea of a thing, even if it's just a collection of barebones 3d models and a neural network trained to animate them that then provides reference images into an AI that turns that into art, sort of like a very fancy automated rotoscoping system. That would probably be enough to make them get things like number and position of fingers and limbs right, at least.