Front Row at Marc by Marc Jacobs

Marc Jacobs sat front row at the show with Alexa Chung, Atlanta de Cadenet, Delphine Arnault and Sofia Coppola.

DELPHINE AT MARC: Katie Hillier and Luella Bartley have long been in a passionate choke hold with the cool girl set going back to Bartley’s own label, and they were all out in force for the debut Tuesday afternoon of the new creative director and design director, respectively, at Marc by Marc Jacobs. Delphine Arnault, a very powerful kind of cool girl, was joined in the front row by Xavier Niel, the French billionaire Internet entrepreneur.

It was a rare appearance during New York Fashion Week for the daughter of Bernard Arnault and second in command at Louis Vuitton, and a quick one — she would fly back to Paris Tuesday evening.

“I was in New York and I love what Marc [Jacobs] does and I’m very pleased to see the show today, very excited,” she said demurely. The rest of the front row was more of what you’d typically expect for the label — Alexa Chung, Atlanta de Cadenet, Sarah Sophie Flicker and Sofia Coppola, seated right next to Jacobs, who sported a casual, all-red tracksuit look.

“She’s like an icon in Britain, Luella, and that brand was the first experience I had with fashion. She was one of the first designers to let me borrow things,” Chung said. “She just makes my dream clothes.”