How is humor used when the narrator puts on a pair of sunglsses to escape Ras's goons

Noticing some men with dark glasses, he is struck by the idea of a disguise and buys dark, green sunglasses. A woman approaches him calming him Rinehart and he play along at first until she gets mad. He picks up a wide hat and is met by more Rinehart greetings. People think the narrator is the illusive Rinehart.