The edges of the rose have a white line that looks oddly pixulated to me. Especially on the top right of the rose. Makes it seem like it isn't a real flower. Did it look like that in the native resolution? Did you use unsharpen or something in photoshop that might have created that? Just wondering. Still a good effort.
Really nice detail on the rose. I think I would have increased the contrast just slightly, because in the shot the whites aren't quite white and the blacks arent quite black.