Singer Rihanna poses at amfAR's fifth annual Inspiration Gala in Los Angeles, California October 29, 2014. (Photo by Mario Anzuoni/Reuters)

A gallery assistant poses with the 1972 work “Secretary” at a press viewing of the artist's exhibition “Allen Jones RA” at the Royal Academy of Arts in London November 11, 2014. (Photo by Neil Hall/Reuters)

Fans cheer in the stands ahead of the CFL's 102nd Grey Cup football championship between the Calgary Stampeders and the Hamilton Tiger Cats in Vancouver, British Columbia, November 30, 2014. (Photo by Todd Korol/Reuters)

Ice covered leafs are pictured on a tree near Amstall in northern Austria, December 2, 2014. Freezing fog and rain covered parts of the region with ice, causing blocked roads due to fallen trees and closed schools for security reasons, local media report. (Photo by Heinz-Peter Bader/Reuters)

Models walk the runway at the annual Victoria's Secret fashion show at Earls Court on December 2, 2014 in London, England. (Photo by Tim P. Whitby/Getty Images)

A dog sits with a competitor dressed as Santa Claus before an annual charity Santa fun run in Loughborough, central England December 7, 2014. (Photo by Darren Staples/Reuters)

Bison along the Bitterroot Valley's Eastside Highway north of Stevensville, Montana, are covered in snow following a blizzard on November 23, 2010. (Photo by Perry Backus/The Missoulian)

Two stallions confront each other at a horse fighting contest in Rongshui, China. More than 30 horses from surrounding regions took part in the traditional activity of the Lantern festival. (Photo by China Foto Press)