Hmm... Seems potentially spurious to me. They use personal website pictures, and have people rate them.

They note in the paper that they could be confounded by picture quality, e.g. successful and ambitious people bother to get good photos done / optimize that aspect.

Then they a) say well we don't think that picture quality will have much effect, cite cite and then they say b) it does have a small effect, but we control for it by controlling for picture size, dress code, and whether a person is smiling.

What a reductionist control, and b) contradicts a). There are lots of things like posture, style and conformance to fashions as to what successful economics academics look like that they do not control for