premise: Tilda Swinton acts.
hypothesis: Katherine Matilda `` Tilda '' Swinton ( born 5 November 1960 ) is a British actress , performance artist , model , and fashion muse , known for her roles in independent and Hollywood films . Swinton won the Volpi Cup for Best Actress at the Venice Film Festival for her performance as Isabella of France in Edward II ( 1991 ) . She next starred in Sally Potter 's Orlando ( 1992 ) , and was nominated for the European Film Award for Best Actress . She then starred in the crime drama Julia ( 2008 ) , I Am Love ( 2009 ) , and the psychological thriller We Need to Talk About Kevin ( 2011 ) . She is also known for her performances as the White Witch in the Chronicles of Narnia series ( 2005 -- 10 ) .