I just figured something out: Betty has a clear vision of who she is. The thing is, she very rarely expresses that vision; she very rarely even allows herself to know she has that vision.

In Shoot, she has perhaps her most revealing therapy session. She talks about how important it was to her mother that Betty be beautiful, how she pushed her in that direction. But then, when Betty became a model, her mother disapproved strongly; called her “a prostitute” (which is holy shit, pretty nasty).

Now we see her anger at her mother, and also her anger at Don (although they don’t discuss that). Just as mother tried to stop her from modeling, Don succeeded at stopping her (by getting her pregnant and marrying her and moving her to the suburbs, away from the Manhattan modeling world). As she tells the story of the end of her modeling career, her voice gets flatter, less animated, sadder word-by-word (great acting, that).