I'm sorry, this is my first critique so be prepared for some fumbling.
Analysis I would like to say that to me this photograph is really beautiful. (okay, I think I'm doing okay so far ^ ^) And where her blue eyes could've been washed out in a face as pale as it is, the fact that she is surrounded by black (i.e. her hair, the mask, the top), they instead stand out. And although I wouldn't say there was much expression in her face, except from maybe earnestness- her eyes (as I've talked about before) definitely create an impact. *Her clothes are very delicate and intricate, which contrasts against her simple yet bold makeup. I can't say much about the technique (as I don't know much about photography), but I noticed that her face (especially the area around her eyes) is sharper than the rest of the photo, apparently to emphasis her expression? I don't know, sorry. Anyway, this technique definitely contributed to the impact of the photo.
But all in all, I really like this. And I don't what to tell you to improve, because a photograph is a moment frozen in time, and that moment's passed... plus every photograph is different.