If they were equals that whole thing wouldn't have happened. Peggy was tripping because despite all of her accomplishments, her moves she in her heart of hearts knows that Don's the man for a reason. She's trying to get there still. She thought she'd made it, but now she's seeing that even with all this, she doesn't have that genius that he has and she's still trying to tap into it.

Great scene though, maybe she won't treat him like garden shit anymore.