I love the "pose" of the snake. Maybe you could've taken it from a straight-on perspective so you could have seen both of it's eyes. The detail is very nice.
He looks so comfortable, The colors in the snake a beautiful and nice focus. I agree with the comments on cropping I'd like to see it with the left side and bottom cropped to bring more attention to the snakes head. I didn't vote on this challenge but I'm scared of snakes so I tend to vote them a little higher for bravery.
I didn't vote on the pattern entries and didn't see the photographs until this morning. When I saw your entry I thought what great focus and lighting. This must have been difficult to achieve through the glass in the low light conditions. Good work!
I like the perspective on this a lot, and the colors are rich and pattern lovely. I think a tighter crop might have bumped you even higher, as the detailed rock takes focus off snake.