I never really got the sense that Karens were upper-class; they’re more like middle-class — and sometimes even lower-middle-class — climbers.
To put it charitably, they’re people who believe they deserve better than whatever it is they’ve got, and they’re not afraid to upset others by insisting on it.
Even the classic Karen aesthetic follows from this. They want to be seen as stylishly rising above other suburbanites, but have a conservative mindset (they’re not about to go starting a hipster coffee shop), and view themselves as practical — and busy — people. The swooped-over bob ‘do achieves all these things: It’s low-maintenance like the classic “Mom cut” (IE pixie/bob) it derives from, and the asymmetry adds a sort of ‘flair’ that any suburban hairdresser can pretty easily accomplish [ed: for ~$40]. The shades, the earrings - these are cheap baubles, but together, the entire ensemble creates an intimidating mien that says, “I’m here, and I’m in charge, because I’m the one that matters”.
Most of the Karens I’ve ever personally met, are not actually all that oblivious about how people perceive them; they just don’t care, because what they want is more important to them. They have goals and dreams - however petty and bourgeois they might be - and they’re not about to let anyone else get in their way.
But yeah, these are all hallmarks of people who aren’t really all that upper-class, let alone upper-middle. They’re middle- or lower-middle-class people who think that customer service would be more deferential to someone of the rank they’re aspiring to, so dammit, they’re going to insist on being treated with that same deference.
Again, this is all charitably speaking. Our attempt to understand the Karen does not make her actions OK, nor does it erase the blind exercise of raw privilege she embodies.
Would it be safe to say that Karens are part of the "Working Rich" (anti-intellectualism, authoritarian, meritocratic) or stagnant Middle Class (insufficient college education but frequent abuse of virtue ethics). Alex Danco might classify them this way https://alexdanco.com/2021/07/08/michael-dwight-and-andy-the-three-aesthetics-of-the-creative-class/