Sienna Miller unveils chic new hairstyle at Matthew Williamson launch party

She's known for her trend-setting style and unique sense of fashion.So when Sienna Miller stepped out last night with a chic new hairstyle at the launch party for the collaboration between Matthew Williamson and Belevedere Vodka, she undoubtedly prompted thousands of fans to dash to the hairdressers.With a thick fringe and choppy layers, the new style framed Sienna's face perfectly.