The resemblance to Lord Voldemort is ironic, because in Harry Potter's last year Lord Voldemort came back to power and controlled Hogwarts, too. So in this year a portrait of HIM would have been normal. Harry granger 19:28, May 20, 2011 (UTC)
Either Easter Egg or perhaps a painting of Salazar Slytherin, his ancestor?
08:41, January 26, 2012 (UTC)