Season six has ended; let the exegesis begin.
Actually, to say this is to sell Mad Men short; the exegeses began when the season began in April, and what we saw when it ended Sunday night was simply the climactic tsunami. Websites are insatiable maws, and Mad Men fed them; for instance, newrepublic.com rounded up four reviewers— Jane Hu, Evan Kindley, Lili Loofbourow, and Phillip Maciak—to post weekly “letters” about the series.
Kindley, after episode seven: “The asymmetry of information thus cuts both ways: Sylvia doesn’t know that Don knows that she doesn’t, in fact, have to get home (or that she gains power by delaying, and making Arnold wait); but Don doesn’t know what Sylvia knows (whether she desires or intends to return to Arnold at all). It’s a BDSM twist on the classic prisoner’s dilemma: effective collaboration and trust between the two parties is impossible, precisely because neither is fully aware of the stakes of the situation.”