I recall a poster on another forum who works on CGs remark that hair textures alone can run up to a hundred MB...
And then there's the skin... if we consider how many CGs we have seen where CG-rendered humans can't shake that "waxy" look, we can appreciate how difficult it is to get skin to look like that. Besides hugh demand for computational resources, skin textures may well run to several hundred MB...
Hair texture a hundred of MB ? please that's overkill.... A 256*512 +alpha+aniso specular should be more than enough to achieve the hair effect in that picture
it's mostly polygons +physics on exoskeleton to make them move.
And for the Skin,2-3 layers of blended procedurals texture should do the trick.
Art is above tech.