The Lucas Museum of Narrative Art opens to the public today, 22 September. Three days before that, Los Angeles held the gala for it, and Kim Kardashian and Lewis Hamilton arrived separately but dressed by the same house: Saint Laurent.

Kardashian wore a black gown covered entirely in sequins, with a mandarin collar in the cheongsam line. It is an archive piece — Yves Saint Laurent's autumn-winter 2004 collection, Tom Ford's final season at the house — worn with Oscar Heyman earrings and a Zydo ring. The look was put together by stylist Law Roach, who announced the new working relationship with two words: “New client.”

Hamilton wore a Saint Laurent suit from the house's current era under Anthony Vaccarello. The two did not pose together on the carpet; the photographs of them side by side were taken inside, at the party itself.

The evening was a preview: the museum received its guests three days before letting the public in. Tom Cruise, Steven Spielberg and Pharrell Williams were listed as co-chairs, and the arrivals included Katy Perry, Oprah Winfrey, Justin Trudeau, Leonardo DiCaprio, Robert De Niro, Al Pacino and Harrison Ford — most of Hollywood in one room.

George Lucas and Mellody Hobson spent years building the museum itself: a new building in Exposition Park in Los Angeles, given over to art that tells stories, from illustration and comics to film. Today is the day it opens its doors to visitors.

The archive choice matters more here than the label. Gowns pulled from old collections have become a genre of their own on the carpet: they read as a knowledge of fashion history and as a refusal of the dress made for a single evening. Tom Ford's 2004 season is among the most quoted in that genre, and Law Roach, the stylist best known for his work with Zendaya, assembles such looks about as often as anyone in the profession.

It is worth naming what this story does not contain: neither Kardashian nor Hamilton said anything about the status of their relationship. What is known about the evening is two Saint Laurent looks and the photographs taken together inside the museum.