This is frustrating as hell. I go to the (minor) trouble and (equally minor) cost of getting myself a light box to show off my painted miniatures in all their glory, and the first figure I photograph looks like she's been attacked by a facehugger. I have absolutely no idea what's gone wrong here; she looks fine in both natural and electric light. Put her in a light box, though, and she looks like the Slenderman sucking a mustard lozenge.
I spent some time tonight looking at her face, trying to work out what to do to help, but the truth is there's nothing I want to change. I thought redder lips, but her face is too small for that; it'd look ridiculous. I think I'll just have to keep experimenting with the box and my camera.
Alternatively, I could stick to painting miniatures with sensibly-sized heads. The Vampiress' face is absolutely minute. I include the Warrior from the base game in the photo below for comparison. You could fit her entire head inside his nadsack.