Every girl has different reasoning for not showing their faces and when they do. Some of the ladies will not show their faces even on the monitors in our bar, but are comfortable with posting their photos on twitter because they can set their privacy setting to where only the people they wish can see their photos. Whereas the world can see her photo on the website and she has no control over it. If you are curious about a girl in particulars reasoning, your best bet would be to ask her, as usually here everyone is different lol!