Fashion Advertisers Rediscover Black Models

Mixed casting also reflects a pronounced shift in brands’ consumer base. “We’re not living in silos,” Mr. Laird said. “Fashion is global. Valentino is no longer just an Italian brand. The woman in Shanghai, Dubai and on Madison Avenue, they all may be Valentino customers.”

Brands courting those customers have raced to keep pace with a culture that venerates Beyoncé, whose musical film “Black Is King” has fired the pop imagination, and Michael Jordan, the focus of “The Last Dance,” a documentary that follows the rise of the Chicago Bulls and the lead-up to Mr. Jordan’s final season.

But real advances, some suggest, will occur only when people working behind the scenes have a voice in determining who gets a star turn in front of the camera. “This is not just about diversifying the talent,” Mr. Bart said, “but about asking who are the casting directors, the creatives doing the hair, the stylists, the photographers?”

Two years ago, Vogue signaled a swing in direction, assigning a 23-year-old Tyler Mitchell, the first African-American to shoot a Vogue cover, to capture Beyoncé for its September issue. That move roughly coincided with significant changes in fashion’s top echelons.

A year earlier, Edward Enninful, a Londoner of Ghanaian descent, had been named the editor of British Vogue. In 2018, the African-American Virgil Abloh was named artistic director of the Louis Vuitton men’s wear line. This summer Samira Nasr, a woman of Lebanese-Trinidadian heritage, became the editor of Harper’s Bazaar.

“I feel a great sense of urgency,” Mr. Bart said. “This can’t be just a passing moment.”