A recurring device used in “Hands and Knees” has characters putting on performances for the benefit of others upon exiting private personal conversations. While this device is overtly employed throughout the episode, the last occurrence of it is perhaps the most subtle and interesting.
Joan first does this with Roger after informing him that she’s “late.” Upon leaving his office, she stands in the open doorway and improvises an imaginary work discussion within earshot of any nearby office worker. Later, concerned their phones may be tapped, Don and Betty awkwardly put on a similar show (reminiscent of The Sopranos or GoodFellas) as they end their call.
After an emotionally distraught Don reveals his true history to Faye, she checks in on him at SCDP the next day. He seems much better than previous night and they make weekend plans. As she leaves, Faye grabs a folder and pointedly repeats Joan’s doorway performance from the start of the episode.
“Hands and Knees” ends with Megan giving Don the Beatles tickets and making her exit. Don is shown watching her through the doorway as she applies lipstick. The initial reaction this moment elicits is “uh oh,” as viewers cringe at the thought of Don making another sexual advance toward one of his subordinates.
However, as noted above, this moment may be a more subtle use of the doorway device. Megan is standing in the doorway putting on her make-up – a mask for the benefit of others. The night before, in the throes of a severe anxiety attack, Don clearly wanted to put an end to the life of deception he’s been living and literally tears off his “costume.” Now that the crisis has passed – Pete drops the NAA account – Don, back in shirt and tie, seems clearly less enthusiastic with Faye about resolving his problem (all bets are off as to whether or not Don is less enthusiastic about Faye too). After everything appears to have been “worked out” (Don got the Beatles tickets, after all), his regard of Megan’s actions in the doorway may represent Don putting his own mask back on as well and returning to “business as usual.”