Basic Trope: Character insults another person or otherwise acts poorly in front of a stranger, only to learn later that said stranger is somebody important.
Straight: Dave complains to a stranger about how he's just been assigned to work under Eva, who he's heard is a nasty piece of work. Of course, he doesn't realize that the woman he's telling this to is Eva.
Exaggerated: First Dave insults his new boss Eva, then when the stranger tries to defend her, gets into a knock-down, drag-out brawl... with Eva.
Dave: Why do they keep bringing in total strangers to lead our division? Eva: I don't think I can say. Dave: Whatever — I just think they could do better if they promoted someone who already had a connection to us.
Dave makes a neutral remark about Eva to a stranger, only to find that stranger is Eva.
Inverted: Dave describes all the incredible stories he's heard about how awesome Eva is... to Eva.
Subverted: "Oh, hey, I'm not that Eva — I'm just a contractor here."
Double Subverted: "Hey, relax — I'm not that Eva. If I were, I'd fire you right now."
Parodied: Eva is wearing a name tag, and went up to Dave to introduce herself. Dave fails to notice and badmouths her anyway.
Zig Zagged: Dave insults his new boss Eva in front of a stranger, whom he later finds out is named Eva. It turns out to be another person named Eva, but Dave's boss Eva overhears the insults, and fires him anyway.
Averted: Dave simply watches what he says around people he doesn't know.
Enforced: "We need a good way to establish that Dave is naive, candid, and unobservant."
Lampshaded: "Dave, you really have a bad habit of talking about people when they're right in front of your face."
Exploited: Felicity knows that Eva has been charged with firing at least one employee, so she sends Dave to talk to Eve without telling him who he will be talking to.
Defied: "Man, that Eva, she... wait, you're—. Never mind."
Discussed: "First rule of not getting in trouble: never say anything you wouldn't want to see printed on the front page of the New York Times."
Deconstructed: Dave complains about Eva, to Eva. Eva fires him for undermining her authority, and now Dave can't provide for his family. Dave has learned a harsh lesson about harmful gossip and showing respect to someone even behind their back.
Reconstructed: Eva likes to leverage Career Building Blunders and rehires Dave, reasoning that Dave will be more grateful than her other employees — and more tactful in the future.
Played For Laughs: Carol, who was standing behind Eva, resorts to more and more elaborate signals to warn Dave to stop as he digs himself deeper and deeper.
Played For Drama: Dave really needed that promotion, but Eva was picked instead. Frustrated, he vents about this to a stranger at the local pub, making nasty insinuations about her sleeping her way to the top. Naturally, he doesn't realize that this is Eva, who's none too pleased about his accusations...