Here's the thing: green lights aren't green because there's something inherently go-ful about the color green. A long time ago, green got assigned to go, red to stop, and that's the semiotics of traffic.
The same is true for this class of luxury goods. There's nothing about too thin, too pale and really sad that implies that people will want to buy an expensive good, and in fact, there is probably data that shows that happy people actually lead to more sales. But these ads are about labeling and fitting in and sending a coherent signal. "Brands like ours advertise in places like this with ads like this."
In the tech world, ads featuring fonts like Myriad Pro and Helvetica send a similar signal. Creative people fall into the trap/use this shortcut of fitting in all the time, because so many other elements of their work feel risky, they choose to do what feels safe when the committee starts making ads.
And we make the same risk-averse decisions when we decide which trade shows to show our wares, what sort of stock photos to put on our website and alas, what sort of entrepreneurs we invest in. Culturally driven choices, not based on fresh analysis or actual impact.
We confuse the size of a diamond with how big a commitment of love the groom is making. We assume that movie characters that smoke cigarettes are more heroic or brooding. Or that how famous a college is has something to do with the future potential of those that attend. Executives assert that office size and inaccessibility are actually correlated with power...
Part of the art of making change happen is seeing which cultural tropes are past their prime and having the guts to invent new ones.