The answer on why the helmet looks tweaked: It's the only way it works with the original model for her to be able to see out. Sometimes functional makes stuff look odd.
As for the making the helmet I used the reflective shapes and colors from a photo of a chrome NFL helmet I googled up. Originally it was 4 layers. Photo Left Helmet, Photo Right Helmet, Photo Left Faux Mandable, and Photo Right Faux Mandible. The Mandable ridges were made with a selection and large, soft brushed Dodge and Burn tools. After all the painting was finished I merged the layers, locked the transperant pixels, ran a .5 gaussian blur and then an unsharp mask at 2px / 100% / 50 threshold.
This is a really nice manip, Quantum. Would it be difficult to shift her helmut slightly to the left? Its just that the whole image is so clean, that it seems a bit out of place.