this is a cool shot i think it could be even better if you cloned out some of the discreet flowers in the background unti l there is only the infocus and black BG
good idea. some leaves edges suffer from low sharpening, well I think you should have considered the low resolution available for this challenge because your image has too detail for 640 pix.7
I like the starkness. There is a good range of gray in there. The only thing that could be improved, imo, is the origin of the flowers. I am confused because there is just a little information behind them. Enough to be a distraction, but not enough to know if they are in a vase or on the bush.