On Sunday evening, the rapper Doja Cat swept into an upscale French restaurant in SoHo carrying a disposable Starbucks cup. She stashed it at the bar, and then made her way to the rear of the room to kiss the actress Pamela Anderson on one makeup-free cheek.

Ms. Anderson was hosting a party with the label Monse as a kind of amuse-bouche for the Met Gala the next night. About 100 designers, editors and models gathered at La Mercerie, the restaurant and home goods store, to greet one another with some version of the line: “I have such a busy day tomorrow.”

Ms. Anderson planned to wake at 5 a.m. — a feat she said would not require an alarm clock — and then head to a park for a moment of peace before her first Met Gala. “I’m going to be walking all of those scary feelings out,” she said.

Under the ceiling’s central arch, servers circulated trays of buttered radishes. Guests sipping Sancerre traded thoughts on increasingly elaborate gala prep routines. (Fillers came up, as did Ozempic.)

Doja Cat said she would be sticking to “regular old beauty prep,” with the help of the makeup artist Pat McGrath.