How we cite our quotes: (Part.Paragraph)
Quote #1
[…] we wear our hair long and dress in blue jeans and T-shirts, or leave our shirttails out and wear leather jackets and tennis shoes or boots. I'm not saying that either Socs or Greasers are better; that's just the way things are. (1.5)
In Ponyboy's town, the way you dress defines what social group you belong to. It's an expression of group identity.
Quote #2
They were the only kind of girls that would look at us, I thought. Tough, loud girls who wore too much eye makeup and giggled and swore too much. (1.76)
Pony judges girls by their appearances, and seems to want these Greaser girls to be more like Social girls.
Quote #3
[…] I wondered what other girls were like. The girls who were bright-eyed and had their dresses a decent length and acted as if they'd like to spit on us if given a chance. (1.76)
This statement suggests that the girls who look nice don't act very nice. But, this is the look Pony is attracted to at the time. So he's engaging in the very practice he hates so much when it's applied to him as a Greaser – judging by appearance and superficial qualities.