Asklemmy

That's not at all what the quote is and neither is the top level commenter's interpretation, and I think it not being these is pretty obvious if you read No Exit. The point that he was making (and this is putting it crassly because I know jack shit about his Heidegger-based phenomenology) is the presence of other people forces us to be self-conscious, to regard ourselves as the object of someone else's perception and judgement. That's why Sartre goes out of his way to say the room (their jail cell in Hell, effectively) had no reflective surfaces, so that the character's perception of themselves could only come from the people they are stuck with (this doesn't entirely make sense, but I am pretty sure it's what he meant). You can read him talk about some of the premises informing this by checking out his writing on "The Look," like is quoted below this comic.

So it's a slightly obtuse point about intersubjectivity that people have turned into a cutesy way of talking about their own misanthropy. It's probably more emblematic of the meaning of the quote how people in this thread, original commenter especially, are talking about silently judging people for this and that action.