Period television uses historical irony to flatter modern audiences with a sense of progress.

Evidence

In the second episode of AMC’s Mad Men, set in the advertising industry during the early 1960s, the young Sally Draper rushes into the living room with a plastic dry-cleaning bag over her head. Her friend explains, “We’re playing spaceman!” Her mother, Betty, scolds her daughter: “If the clothes from that dry cleaning bag are on the floor of my closet, you’re going to be a very sorry young lady.” Early episodes of Mad Men leaned heavily on such historical irony, offering viewers the warm satisfaction of social progress. — W. David Marx, Blank Space, 394