On Sunday's episode of Mad Men, "Lost Horizon," the former SC&P partner and account executive Joan Harris (played by Christina Hendricks) faced more of the odious sexual harassment and discrimination the character's endured over the years. This time, the executives belittling her judgment, ignoring her opinions, and urging her to sleep with them were executives working at her new employer, the advertising firm McCann Erickson.

McCann Worldwide, as the firm is known today, reacted with a series of playful tweets, cut with a snarky defensiveness that indicated the company had taken the episode at least a little personally.

While some brands like Heineken have actually paid for product placement on the show, others like McCann have had to hold their breath and pray Mad Men won't invent a closeted drunkard CEO for them (Lucky Strike); use their product in the backdrop of a suicide attempt (Jaguar); or remind viewers of how they contributed to civilian deaths (American Airlines and Dow Chemical). For brands, a Mad Men mention, or even a full storyline, could summon either excitement or dread; and the way companies react to their portrayal reveals how they're often willing to let themselves be seduced by the show's nostalgic sheen. If the depiction is kind or neutral, it's free advertising. If it's ugly, brands have the excuse that it's just fiction. But either way, leaning into the publicity hints at a willingness to ignore Mad Men's series-long effort to lay bare the hollowness of so many popular products, and the cynical attempts by marketers to tie them inextricably to the American Dream.

Of course, for some brands, the exposure is innocuous, even salutary: The headphone-maker Koss seized on its unexpected Mad Men appearance with a brief marketing blitz, and no one, fictional or otherwise, got hurt. (Let's also not forget the slew of fake or already dead companies that have made their way into the show: Burger Chef, Topaz, Sugarberry Ham, Menken's Department Store, Secor Laxatives). But McCann couldn't back away from its portrayal so easily: For the ad agency, the sexism that pervades the higher rungs of large companies can't be written off simply as a plot device—nor can it be necessarily corralled by claims that the show belongs to a different time.

Perhaps the murkiest and most high-profile instance of Mad Men tying a storyline to a brand involves Jaguar. In a pivotal season-five episode, an executive from the company coerced Joan into sleeping with him to get the account, and the partner Lane Pryce tried and failed to kill himself in one of the cars, which wouldn't start. Initially, the vice president of brand development for Jaguar, David Pryor, told AdAge that the company was "fairly surprised at the turn of events" with regards to Joan, and that "obviously [the portrayal] was kind of tainted," but that ultimately the company was "confident that people know [the sleazy Jaguar executive was] a fictional character." Later, in a post for Jalopnik, Pryor and a colleague described how they felt watching the episode: They tried to "ignore" Joan's storyline, which inspired "revulsion," and they  were sad about Lane's death because "it was Lane who first brought Jaguar to SCDP." All this dissonance and ambivalence aside, the company's verdict was simple: "Our job is to promote the desirability of our cars, not the morality of our fictional executives." Which, fair enough.

But brands are often willing to embrace that fictitiousness when it's convenient. Hershey's was thoroughly delighted by its role in the show's season-six finale, even going so far as to send the show's creator Matthew Weiner chocolate. When Vanity Fair asked what Hershey thought about being linked with Don's childhood memories of living in a brothel, the company said it wasn't concerned—"Obviously we know that this is a fictitious television show set in the 1960s"—but that it found the episode otherwise "wonderful, organic," and "memorable."

Some have complained that the show's nostalgic feel can have a tempering or softening effect on otherwise bad behavior like alcoholism, adultery, sexism, or racism. As a result, it can be easy to take the brand exposure at face value, and to overlook how the show critiques consumerism and the illusory nature of advertising, as well as how it often works its way into the uncomfortable corners of corporate (and American) history. But if Mad Men only reflected on the pitfalls of the past, it would still be at most just a "good" show, despite its superb writing, acting, production design, and cinematography. It's a great show in part because, in talking about the past, it illuminates the flaws of today.

Which brings us back to Joan's McCann storyline from "Lost Horizon." The slightly embarrassed tenor of the company's tweets in response is understandable—no one wants to be associated with the kind of ruthless chauvinism on display in that episode.

But before Sunday, McCann didn't seem to terribly mind the attention Mad Men sent its way. It's certainly not as ubiquitous a brand in the way Hershey's, Coca-Cola, Heinz, American Airlines, or Playtex are, so the average viewer likely wouldn't be curious how the firm would respond to its portrayal. Yet the firm's proactive efforts to gamely play along on Twitter, to make villainade out of the fruit of villainy, paid off in at least one way: Since the show returned for its final stretch April 5, McCann's online mentions/impressions rose 46 percent, according to data reported by AdWeek. But being framed as a subsidiary-swallowing behemoth is preferable to being painted as a claustrophobic den of sexists. Even if the latter portrayal was fake in its specifics, it had authenticity in a broader sense, pointing an uncomfortable neon-lit arrow at the persistent issues of sexual harassment and gender discrimination in the workplace.

Not to mention the advertising industry's own ongoing gender-makeup problem. As FastCompany reported in 2013, while 80 percent of women control consumer spending, just 3 percent of creative directors are women. Just five of the 19 individuals listed on McCann's leadership page are women. With all this in mind, the awkwardly coexisting narratives of, "Well, it's just a story," and, "Thanks for the free publicity," collapse.

Against that canvas, does it truly make sense to embrace the Mad Men spotlight? In purely practical terms, probably, according to Kelly Cutrone of the PR firm People's Revolution:

Does having your products on a popular TV show in a subliminal or obvious way help sell them? Yes, it does. Does it increase awareness and comfort with the product — do viewers feel psychologically closer? Yes, they do.

Still, Mad Men is a show that has little respect for things, products, stuff, and images. It's a show deeply interested in exposing how desire is manufactured, how much effort goes into the appearance of effortlessness, how more can be less, and how the person who has everything can be left with nothing. Though there's always a degree of credibility to be wrung from self-awareness and self-deprecation, these themes are hardly great slogan-makers.

Among the show's most enduring images is the silhouette of a man—the guy who once said happiness "is the moment before you need more happiness" and that "people want to be told what to do so badly that they'll listen to anyone"—falling helplessly past a collage of images promising that fulfillment is just one purchase away. It makes sense that brands and companies like McCann would try to make the most of a Mad Men cameo, however risky. But in light of the overarching message from the show's seven seasons, it's hard not to conclude that they might be missing the point.