In Nanette, a brilliant meta-comic retrospective meets arts-as-activism performance, Gadsby revisits punchlines she’s been delivering onstage for years, as a gut-punch farewell. I remember these jokes from shows past: her slow, deliberate phrasing deployed to get our biggest laughs. But this time, she makes her audience pause to consider these stories. Are they jokes? Are they funny? Aren’t they horrific?