Hairstyle is a visual reflection of a character's attitude, Rivers said.
“I think in any time period you can look and see a person’s hairdo reflects some part of their personality," she said, naming Peggy Olson, played by actress Elisabeth Moss, as an example.
“[She] is a little more conservative, but she’s also a businesswoman and she’s a no-nonsense person," said Rivers. "She doesn’t have a lot of time to do her hair and have a big teased-up hairdo like Betty Francis or an updo like Joan.”
Rivers noted Peggy's look has transformed from a longer, girlish hairdo to a more conservative, shorter look that still isn't as polished as other female characters on the show like Betty Francis (January Jones) or Joan Harris (Christina Hendricks).
“We always laugh, because [Peggy] is always a little off," Rivers said. "Her clothes are great, but there is something a little off about her.”