Without knowing who has created the works, people can bid for them on eBay until the auction, called The Big Art Secret, closes on Sunday. Proceeds from the sale will go to St Wilfrid's Hospice. Hockney's work is "an ink and colour crayon drawing on a postcard" and Emin has donated four postcards.
The world-famous artists have contributed pieces along with other famous people including David Cameron and Ronnie Corbett. They have supplied their own mini-creations for the charitable cause. Their works are being exhibited at the Towner art museum in Eastbourne.