A rare portrait of Diana, Princess of Wales, sold for more than $200,000 Thursday, fetching ten times its highest estimate, according to auction house Sotheby's. The oil on canvas painting by late American artist Nelson Shanks depicts a pensive Diana looking down to her right side, as if deep in thought. The head study was completed during the more than 35 hours of sittings Diana had in 1994 for a separate full-length portrait. That portrait was originally hung in Kensington Palace, but now hangs in her ancestral home in Althorp in Northamptonshire, Sotheby's said.