Maybe she just enjoys looking her best.
Do these jeans make my butt look big?
If your girlfriend is checking her butt out in a mirror deciding if her butt looks good enough in them before going to the bar would you say she was worried what the other guys would think or seeing it looked good enough for me?
She just wants to look good. If the other guys think her butt looks great, take that as a compliment. After all, you're the one going home with her.
She doesn't care what any man thinks. She is making sure it looks good enough to keep snarky women from making comments about her butt.
-It could be anything! But i'd say, She wants to look good for herself. (we don't live our lives for others, so this matter shouldn't be necessarily for others) everyone would like to look at their best and everyone care about different details entitled to their own opinion and how they feel.
-However, i give her the right to try to look good for others too. Not necessarily guys but people. She's not my shirt, i don't own her. She deserve to care about her look and be willing to look good and get admired by everyone. So i also help her to take the best out of her.
-If she's too sensitive on how she looks and what others thinks. I try to acknowledge her that it doesn't matter what i or others think. You must wear as you feel comfortable. Then you look at your best then.
-If she having body image issues and displeasure of how her physical shape displays. I'll do my best to confident her and gets her out of the situation.
Neither .. She is checking to see if it fits HER approval. A woman's looks often forms how she feels about herself.
Inferiority complex here. She is worried about how others think about her looks. Usually is a little conceded here doing this but then women are women who are always worried about how they look, like some Model Agency is going to offer them a job. They never understand that real men go for more than just looks and if any guy she is with just best compliment her whether true or not if he wants to live
If she's your girlfriend, why not ask her?