If I'm not mistaken, I've lauded this Twilight series possibly to the point of excess; still, it's such a great Cosplay shot, and it captures that natural state of frustration Twilight seems to exist in despite her good, if not completely peppy, cheer. I've always attributed it more to her feeling as if she never knows *enough*, which is why she always seems like she dissatisfied that the world isn't like it's depicted in books. If she knew more, she'd understand things better.
Perhaps I'm look far too into things, but I feel like that's the deeper meaning behind your poise and expression here. Seemingly relaxed, but frustrated. Again, there's also such a fantastic level of sexy fun (Not sure when sexiness isn't fun...) in the shot. The classic depiction of the girl who's hot, but doesn't realize she is because she doesn't openly try to be. Also, a quick praise for your eyes. Not sure if the effects are from the contacts alone, but there is this great ember light quality; very 'magic within.'