It’s about the way Zois smile. In the current version, it’s a grimace. It’s very unnatural. With male Zois, it looks even worse.
Current version
and my awkwardly corrected one
I think it would look better if Zois didn’t bare their lower teeth so much and maybe it would be okay.
The thing is, when you work hard on the details of Zois’ faces and in gameplay the end result looks terrible. Sometimes it completely changes the target facial features that you set.