The shadow thing shouldn't even be debated. It's a shadow of her face and you can even see her eyelashes in the shadow!
A bit of the PV and making of how beautiful you are were shown on Mezamashi TV today in Japan.
浜崎あゆみ 新曲プロモは強風の中で
歌手が歌う「how beautiful you are」のプロモーションビデオが届いた。このビデオは様々な愛の形を表現する事をテーマに、強風に立ち向 かっていく姿が描かれている。この曲はアルバム「Party Queen」に収録されている。
The theme is "love" expressed in a variety of themes. It does seem a bit like Christina Aguilera's Beautiful.
Source
People on Twitter have said that the PV is very beautiful/pretty.