The two most luxurious auction houses in London, Christie's and Sotheby's, are getting ready for their summer sales with some of the finest art pieces from Picasso, Manet, Dali, and Magritte. At Christie's, the Picasso's painting is estimated at 6 million pounds, whereas the Manet at Sotheby's could be sold for around 20 million pounds. Duration: 00:51