He always looked good when he was finished fixing himself up, but he was a secret slob anyway, if you knew him the way I did.
This passage occurs in Chapter 4, when Holden is watching his roommate Stradlater get ready for a date with Jane Gallagher. The quotation indicates that appearances are deceptive. Just as Stradlater might look good but is secretly a slob, he might seem like a good person because he’s well-mannered and friendly, but he’s actually mean (he punches Holden), lazy (he asks Holden to write his paper for him), and conceited (he brags about his sexual encounters.) Holden finds this gap between appearance and reality disconcerting. Indeed, this gap drives his obsession with the phoniness of the adult world.
But it was freezing cold, and I took my red hunting hat out of my pocket and put it on—I didn’t give a damn how I looked.
After leaving Ernie’s piano bar in Chapter 13, Holden decides to walk the 41 blocks back to his hotel in the cold. Holden is from a wealthy and privileged New York family, with a mother who has “terrific taste” in clothing. He has also been surrounded by similarly wealthy and stylish people like Mr. Antolini, Carl Luce, and Stradlater. In this world, appearances clearly matter. Given this context, for Holden to say he doesn’t “give a damn” about how he looks is shocking and rebellious. This statement therefore marks Holden’s rejection of the world in which he grew up.
I couldn’t picture her doing anything for charity if she had to wear black clothes and no lipstick while she was doing it.
This quotation appears in Chapter 16, shortly after Holden says goodbye to the two nuns he meets over breakfast at Grand Central. Holden tries and fails to imagine women like his aunt collecting money for charity in plain clothing, like the nuns. For women like his aunt, charity events involve a great deal of pomp and circumstance. In this sense, charity itself becomes a kind of lipstick: something women of Holden’s social world put on for the sake of appearances. In other words, what really matters to women like Holden’s aunt is looking good, not being good.