To be completely honest, this is one of the best Jack Frost cosplays I've come across. It looks like you put a lot of effort into making it. The hair is... undoubtably the best I've seen yet. The locks fall in the right places, and the white isn't... too white, if you know what I mean. Fake, if you will. It's just right. The frost patterns on the sweatshirt are beautifully done, not overpowering in any way, but subtle, like they should be. The staff is very cool as well; my only comment on that would be to make it slightly darker. Not a ton, just enough so the frosted parts stand out a bit more. Another thing I'd like to comment on would be the expression. Jack Frost is the Guardian of Fun; the look on his face seems a bit too dull. If you're trying to go for one of his more thoughtful, longing expressions, I wouldn't look so directly at the camera. The picture would have a better sense of distance, as well as emotion. And... I can't quite tell, but I think the model is also wearing white eye-liner if I'm not mistaken? It was a creative touch, but it makes him look weary, almost tired. I would just try to steer clear of that next time around.
Overall, this picture was fantastic! I love the detailing, and you paid attention to the little things, which is always important. Great job!
I gotta say that's some nice Jack Frost hair you got there. It's isn't horribly gelled or clumped up like others out there I've seen and it looked natural. Aside from the long sideburns, it looks like the real deal. I could get easily convinced with that look.