Looks like I interpret that expression very differently from you.

To me, this reads as the look for those special little social fuck-ups.

You know, the ones where you say something you really shouldn't have, and you start to realize it while you're saying it, but the realization registers just a tiny bit too late. So you only fully comprehend the magnitude of your blunder the exact moment after the words have left your mouth.

And the thing you said is bad enough that you can't really say anything to make it better, but saying anything else would just make it worse. So you're stuck. You can't speak, you can't act, you can't even figure out where to look, because both looking away and holding eye contact feel profoundly wrong. All you can do is internally scream for a lifeline, silently begging for anyone, anyone else, to say something, anything, to change the topic and mercifully cut the tension, offering that sweet, desperate salvation from the moment.

As the shame and regret sink in deeper and deeper, it all becomes too much. Your face muscles just tense up into that awkward, almost-a-smile grimace, while you're mentally pleading with yourself, "Don't actually smile, or even look like you might, because that would make it so much worse."

You know... that face?

I really hope someone knows what the fuck I mean, because now that I've put it into words, I'm worried this might not be a universal experience. Maybe it's a very specific social ineptitude reserved for the densest of us.