I asked that question in the stream. Unfortunately you will take the default race look of that gender. So if you are a male undead and you steal Griff's face (example i used in stream question) you will look like the default human male, not Griff.

I think it is a bit of a shame but hey who knows maybe you can wear the mask and change the race appearance with the mirror on lady vengeance.

You won't be able to pretend to be Griff and give orders either. But i guess implementing that would be way too complex and a giant pain in the butt.