Nearly two decades after their first collaboration launched a 14-year-old Kate Moss into fashion super stardom, Corrine Day's challenge was to present a fresh portrait of one of the world's most photographed women. The commission, by the National Portrait Gallery, was never going to be easy. "To be honest, I wasn't sure it would work," said the gallery's director Sandy Nairn.
"I wasn't completely convinced there was anything new to be got out of the subject." But he called the finished work "extraordinary".
"I think when you see it on the wall, even if you had no idea who Kate Moss is or what she's doing there, it draws you in and sets you off on a process of inquiry." Day said the photos were taken while talking. "I suggested to Kate that we have a conversation about a serious subject. The subject she chose to talk about revealed her true feelings and in turn defined her character."
Neo-classical endogenous growth theory? The carbon footprint of a globe trotting supermodel? What to do about Pete Doherty's spots? We do not know.
"I think in a way that's part of its quality," Mr Nairn said.
"It's almost like one of those Victorian scientific studies of the emotions - in some of them she looks as if she is about to speak, or has just finished speaking -but we don't know what she would say."
The gallery already has conventionally glossy gorgeous images of Moss by fashion photographer Mario Testino. The idea of commissioning Day came because she was already working with the gallery on the Face of Fashion exhibition - for which Moss is the poster girl - opening later this month.
The two have worked together for years. Day was herself a model, before becoming a self taught photographer, who has developed friendships with many of her subjects.
She was one of the first to work with Moss , and shot the cover for The Face magazine in 1989 which made her famous. The exhibition will include another unpublished image from that shoot, as well as the work of other fashion photographers, and models including Madonna and Brad Pitt.
The portrait will go on display later this month, to coincide with the exhibition. And Moss's opinion of the finished product? She apparently looked at the images - nine separate close-up shots framed together as one work - and saw "crooked teeth and a wonky nose".
Â· Face of Fashion, National Portrait Gallery, February 15 - May 28.