I think this may actually have been better without desaturating the scene. Or if the artist herself was also in color - I would agree maybe the rest of the background is superfluous and could be distracting if colored, but making the artist B&W somewhat draws her out of the photo.
nice b/w and a good job of selective de-sat and clearly candid. I would have preferred to see more of her face and less of her lower torso. Would probably be even better suited to the challenge if the emphasis were on her rather than her art