Lisa Wade at Sociological Images muses on why commercial depictions of “lust” or “sexy” overwhelmingly involve images of women, making the implicit lust-er or perceiver-of-sexiness a straight male:
Thought Experiment: If nearly naked men had been dancing in those columns, do you think the audience would have thought “hot men for the women!” or “how gay!”? I think many, if not most, would have thought “how gay!” A female gaze that validates women’s sexual subjectivity and the sexual objectification of men is simply less accessible for both women and men. I think if men were dancing in the columns, an objectifying male gaze would still be at play, except this time the gaze would have been aimed at men.
Wade attributes this to the “primacy of the male gaze” and the presumption that the default perspective is male. Which is probably no small part of it, but I think there’s some other stuff going on here as well. First, there’s a widely held belief that men are much more responsive than women to visual sexual stimulus. Recent brain research suggests that this may, in fact, be a myth—but the idea is widespread enough that a marketer trying to use sex to sell in a visual medium may just be trying to maximize the effectiveness of their ad.
But I think part of what’s lurking here has to do with the way homophobia tends to be asymetrically focused on male homosexuality. The bogeyman for social conservatives seems to be gay men far more often than lesbians, and anxiety about being perceived as gay seems to be a much more pervasive straight male phenomenon. This affects norms even in pretty gay-friendly circles: I’m not likely to tell a straight male friend his new suit or haircut looks “super hot” or greet him with a kiss on the cheek—even if I know both of us do those things with our gay male friends. Which is to say, even if we’re both fine adopting the gay norm of interaction when it’s seen as the other person’s norm—when in Rome and so forth—there’s a residual anxiety about being the one introducing it. This is pervasive enough that it even shapes our private reactions: I’m also not that likely to see a Dior ad in a magazine and consciously form the thought “wow, he looks hot” even as a sentiment of simple aesthetic appreciation. Of course, if the ad successfully motivates me to think that maybe I would look good in a similar suit, I must at least implicitly be thinking something like that, but my tendency will not be to explicitly represent it to myself in those terms, something women generally seem more comfortable doing. And since our culture doesn’t seem to burden women with this particular bit of psychic baggage to the same extent, the straight-male image of “sexy” probably really is more “universal” in the sense that it’s more capable of being processed as “sexy” by both men and women, which again makes it more viable as a “generic” image for marketing purposes.