This is a really neat photo. I like the 'abstract' nature of it. I also think you chose a very nice composition on this shot. Tying the ice into the theme of 'blue' was a bold attempt with black and white. The visible detail in this shot is quite nice, but, IMO, it is a tad on the dark side. I personally would have liked to seen this shot a tiny bit brighter for this challenge.
I think this photo is a bit underrated as far as the score is concerned. Reading through the comments you received, there are two items that stand out. 1) It's not blue. 2) What is it? Unfortunately, I believe that the majority of the voters probably rated your photo lower because it did not contain any blue. I know what the challenge description said, but I don't believe voters give much latitude on a bold attempt such as this one. Those who could not tell what this is probalby have a sever monitor calibration issue, or they just didn't give it more than 2 seconds of view time.
I think you can improve this image quite a bit more with some minor level adjustments and maybe a quick pass of the sharpen filter. Ice is a challenging subject to expose nicely...
another good use of shallow dof. hope the other voters appreciate it too. the line it forces your eye to follow makes this picture really interesting. 8