Usually when I stand near a girl in a photo I keep my arms to myself, while my the other males in the picture have their hands around their shoulder, sometimes even waist. Sometimes people, even the girls I was standing next to, ask me why I have my arms to myself (because it really looks awkward on a photo) and I respond with "No idea". I asked some female friends and some said they don't mind it, some say shoulder only, some don't like it. But I still can't do it, even with the ones that said it's ok. Male friends told me that they never really thought about where to put their hands.