She walks through the door, but not before miming a quick curtesy, because it feels like the appropriate response for someone holding a door open for her. If by appropriate we mean the exact opposite.

"Now I see what's going on," she shoots him a look over her shoulder once she's through the door, "I'm just here to make you look better by comparison."

Here being some vague area where they're friends who spend lots of time together, as opposed to people who've hung out together twice.