I really love the idea of the picture: It's simple but effective, but: The bottom half of the shot is too crowded in my opinion, the top a little empty, but nice overall work!
This really caught my eye as I was browsing the new photos. The zen-sensibility of the composition is very nice. Simple, yet there is something powerful as well.
There are 256 levels of gray in a grayscale and 16 million levels in a color image. The subject matter you have here normally reflects very subtle changes in tone so that a lot of detail is lost when you reduce those tones by using black and white. It's a nice concept you're showing us but I think it would be much better served if you had presented it in full color. Just a thought.