This is a great bust, and also a tricky one for rookies like myself. The suitable absence of folds in some large surfaces can really make a fool of those with only a basic understanding of high light and shadows.
I can actually visualize a below-average rendition of this bust right now, that is how often I have seen rookies like me stepping right into the trap. Funny thing is we then disgrace ourselves by displaying these joke-like renditions in the local figure modelling venture and attaching an inflated price on it.
Luca would do a great job with this one.