Wow. just... wow. The gradients of grey of her skin, particularly along her left arm are beautifully soft and subtle but of course the key effect in this one is the difference in colour tone between the browns of the chair and background and the more traditional mono tones of the model herself. It really pops her out of the background. That's some artistry at work there. I also love the use of space here; the spotlighting effect on the model (and I don't think she could be better lit in terms of evenness and level of light) is complimented by the halo of light in the upper left, and serves to bring the focus onto her even more effectively than mere empty space would. Beautifully done in every respect.
