In this photograph taken on January 19, 2012, Indonesian schoolchildren hold on to iron cables as they cross a nearly-collapsed suspension bridge at Sanghiang Tanjung village in Indonesia's Banten province to reach their school. (Photo by Kris Aria/AFP Photo)

The space shuttle Endeavour is transported to the California Science Center in Exposition Park from Los Angeles International Airport (LAX) in Los Angeles, California. (Photo by Kevork Djansezian)

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

Socialite Kathy Hilton attends the Prudential Financial Grand Prix Hamptons Classic Horse Show August 31, 2003 in Bridgehampton, New York.

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

Pretty Girls, Ugly Faces is a photo fad in which girls take pictures of themselves while posing in an unflattering manner, making a silly face or performing a physically strenuous activity.