Alice is naked in a place (like, say, a conservative Baptist church in the Deep South during Sunday service) where it normally wouldn't be acceptable. Everyone reacts as if Alice just crossed the Moral Event Horizon.
Zig Zagged: Alice mysteriously switches from naked to fully dressed several times during a scene.
Averted: Everyone remains fully clothed throughout the series or movie.
Enforced: The writer wants to create an awkward situation in a Sitcom.
Lampshaded: "Bob, there's a naked woman sitting on your porch swing!"
Invoked: Alice is visiting a town with a reputation for being so laid-back as to not begrudge public nudity. She doesn't pack any clothes and proceeds to strut her stuff.
Defied: Alice is on a nude beach and is unwilling to take her clothes off.
Discussed: "What is it about nudity that people find so hilarious?"
Conversed: "Ever wonder why all these new comedies keep featuring naked people?"
Implied: Bob asks Charles, "Did you see Alice when you went downtown?", and then bursts out laughing. Charles says, "Yes, I sure did. In fact, I couldn't stop staring at her."
Deconstructed: Because Naked People Are Funny, whenever Alice tries to undress to have sex with her boyfriend, Bob, he bursts out laughing, rendering them incapable of having intimate relations, causing Alice and Bob to suffer much angst indeed.
Reconstructed: However, Alice uses this to treat Bob when he suffers from depression. Intimate Healing, indeed.
Played For Laughs: Alice has her clothes completely burned or torn off by an accident. She decides to walk home and get dressed, only for a Birthday Suit Surprise Party to happen. She screams, "Don't look at me!"
Played For Drama: Alice is arrested for indecency, and Bob murders the police officer who arrested Alice because everyone else in Troperville found Alice's nudity hilarious. Later, we see Alice and Bob sharing a prison cell, and now they're both naked.