“She had on a kind of dirty-pink -- beige maybe, I don't know -- bathing suit with a little nubble all over it and, what got me, the straps were down. They were off her shoulders looped loose around the cool tops of her arms, and I guess as
a result the suit had slipped a little on her, so all around the top of the cloth there was this shining rim."
What surprised the narrator about the girl's swim suit?