Whenever I try to get dressed up to go somewhere, especially if it's casual, like just going out for a walk, or to the store, or something like that, I try to grab something that kind of contrasts a little bit.
The Heeps, mother and son, seemed to me like two ugly great black birds hanging over the house, and they made me so uncomfortable that I went out for a walk in the afternoon.
Some use the term sarcastically to express envy about their coworkers who can stay home, while other " chosen laborers" are just happy they can go out for a walk.