Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Ukrainians wearing traditional costumes sing Kolyadky or Ukrainian Christmas Carols, as a part of Orthodox Christmas in Kiev, Ukraine, Thursday, January 7 2016. Orthodox Christians mark their traditional Christmas Day Jan. 7, with many ancient symbolic events. (Photo by Sergei Chuzavkov/AP Photo)

Claudionor Jose de Deus, wearing a Santa Claus costume, arrives at Santa Rosa community to distribute presents to children, on the shores of the Amazon River in rural Manaus, Brazil, December 19, 2015. Jose de Deus is part of a volunteer group that distributes toys to children from poor neighborhoods and riverside communities that are distant from the city. (Photo by Bruno Kelly/Reuters)

An elephant dressed in a Santa Claus costume gives out gifts to students to mark the Christmas season at a school in Ayutthaya province on December 24, 2010. The event was held as part of a campaign to promote Christmas in Thailand. (Photo by Pornchai Kittiwongsakul/AFP Photo)

Inmates stand next to food during a Christmas event at Sarita Colonia male prison in Callao, Peru, December 18, 2015. For the event, inmates prepared Christmas meals for a culinary competition and took part in dances and songs. (Photo by Mariana Bazo/Reuters)

Pakistani Christian Maria Akbar, 15, checks herself in the mirror, after having her make up done by hairdresser Razia Rehmat, 39, in preparation for Christmas holiday, at a hair salon, in a slum that hosts Christian families, on the outskirts of Islamabad, Pakistan, Wednesday, December 24, 2014. (Photo by Muhammed Muheisen/AP Photo)

Reflected in an ornament, a reporter takes a photo of the White House Christmas Tree in the Blue Room during a media preview of the holiday decor at the White House in Washington, U.S., November 29, 2016. (Photo by Kevin Lamarque/Reuters)