I see that you received several "image is too small" comments on this your first challenge. There is a tutorial by EddyG on this site (click LEARN > TUTORIALS on the blue bar at the top of the page) that helped me a lot... the main thing is to use "Save for Web" instead of "Save As" when you finish editing your photo in PhotoShop.
As for the picture itself, no doubt that it meets the challenge :0} I think one problem voters have with it besides the small size is that the picture itself is bland. The secret in my opinion is to present a photograph that not only MEETS THE CHALLENGE, but is an interesting, appealing photo in it's own right. That is to say, if someone looked at the picture and didn't know the challenge theme, they would still find the picture attractive. Make sense? That concept, incidentally, is one that I'm still trying to master, too.
Unless you have some compelling reason to use such a small image it's a good idea to take advantage of the full 640 pixels that DPC allows in at least one direction.