Oh, is that why none of them are black?

Or even average looking.

In using Stable Diffusion for a DnD related project, I’ve found that it’s actually weirdly hard to get it to generate people (of either sex) that aren’t attractive - I wonder if it’s a bias in the training materials, or a deliberate bias introduced into the models because most people want attractive people in their AI pics

It’s trained on professionally taken photos. Professional photographers tend to prefer taking photos of attractive subjects.