"He was tall and muscular, a blue-collar type" A blue collar worker is lower class by definition. As phrased above, the "tall and muscular" bit is part of the

"He was tall and muscular, a blue-collar type" A blue collar worker is lower class by definition. As phrased above, the "tall and muscular" bit is part of the writer's observation/stereotype that the man is a blue collar worker. "He was big and strong and (therefore) looked like someone who works in manual labour".