I, personally, have never felt marked. Simply because of the fact that my personality, body language, and sometimes even clothes, change depending on who I'm with.
For example, if I am hanging out with life long friends, I'm relaxed. Chilled. I look lazy, wearing an over large sweater and comfortable clothing.
If I am hanging out with some girlfriends, I'm wearing something that makes me look good. Maybe even some make up. I'm more smiley(is that a verb?), and I laugh more.
If I'm just at home, I wear pajamas. I don't even talk unless I need to. There is no make up involved. I hate make up.
When going to school, I try to be comfortable, but still look nice. So jeans and a tee shirt, with a sweater, is usually what I wear. If I wake up early, I wear make up.
I suppose people mark me depending on who I'm with, but I have never felt like I've been judged or marked.