I think it's pretty apparent that they are using a "body model" for the body as well which is kind of interesting in itself...
It used to be that we'd use CG characters to replace the body of actors, now it's the other way around...
Wait, they're just photoshoping her face? That's a whole less impressive than I thought.
I can't prove it but there's evidence of that in the photos (difference in light transport in the facial skin vs body skin, some inconsistencies in shadows, masking issues around the hair , nail polish, the clothing is a little "too real").