Granddaddy Cain's physical size is tied in with his mental strength. He is a tall man with an imposing presence. He's able to unnerve people and make them feel uncomfortable because he says very little, but he also has a dignified presence about him. The narrator tells us that when he was a waiter on the train, people referred to him as "the waiter", not just "waiter" like the others. When Granddaddy does speak, people listen. This is why the cameraman hands over his camera without an argument to Granddaddy when he motions for it. Granddaddy is a calm man, but you know he means business. He's not someone you would want to cross or get on the bad side of.