A rare painting depicting Princess Diana is on display in London until July 6.

Surprise in Britain: A rare portrait of Princess Diana (1961-1997) is on display in London at the Philip Mold

Diana wears a green Catherine Walker slip dress in the portrait. She chose the same gown for her famous 1997 cover shoot for Vanity Fair. However, as the description of the painting suggests, the princess changed into a different, more classic outfit during the sessions. It is unusual for Diana to look down in the portrait. In addition, she only wears one earring.

Art studio was a “sanctuary” for Diana

The portrait is a detail. The later, complete painting now hangs at Althorp in Northamptonshire. Diana posed for the portrait for a total of 35 hours spread over 30 sessions. During this time she is said to have become friends with Shanks and his wife Leona. In a letter to the two, she is said to have explained that the studio was like a kind of “place of refuge” for her.

The portrait fetched $201,600 at auction in January.