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.

South Korean prostitutes hide their identities as they participate in a rally on September 22, 2005 in Seoul, South Korea. Prostitutes rallied against government law aimed at the s*x industry. (Photo by Chung Sung-Jun/Getty Images)

Models walk the runway at the “A Child of the Jago” fashion show during London Fashion Week at the Wilton Music Hall on September 21, 2011 in London, United Kingdom. (Photo by Ian Gavan/Getty Images)

In this undated handout photograph from the “Inside Out Project”, a poster bearing the image of a Pakistani girl whose parents, lawyers say, were killed in a drone strike, lies in a field at an undisclosed location in the northwestern Khyber-Pakhtunkhwa province. A group of artists in Pakistan are hoping to generate “empathy” among US drone operators by placing giant posters of children in the country's troubled tribal regions. (Photo by AFP Photo)

In 1949, LIFE magazine sent famed photographer Nina Leen to document the daily life of a sassy troupe of young women who had run off and joined the famous Barnum & Bailey Circus in Sarasota, Fla. What developed was a portrait of a sisterhood formed over acrobatics that mixed high-flying wire acts with fashionable high-waisted shorts. Sarasota was once considered “the home of the American circus”. Here: an aerialist smoking while rehearsing for the Ringling Bros. and Barnum & Bailey Circus in Sarasota, FL in 1949. (Photo By Nina Leen/Time Life Pictures/Getty Images)

In this March 22, 1975 file photo, a refugee clutches a baby as a government helicopter gunship carries them away near Tuy Hoa, Vietnam, 235 miles northeast of Saigon. They were among thousands fleeing from Communist advances. AP Photographer Nick Ut will be retiring from the AP in March 2017 after 51 years of taking photographs from the front lines of the Vietnam War to the red carpets of Hollywood. (Photo by Nick Ut/AP Photo)

Photographer and artist Jill Greenberg poses at her home to promote her Exhibit “Glass Ceiling: American Girl Doll” And Billboard For LA on September 29, 2011 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images)

Christina Careaga (R) and Hannah Thielmann kiss as they celebrate during the Gay Pride parade on June 26, 2011 in New York City. The parade took on extra significance following Friday night's legalization of same-s*x marriage in New York, often regarded as the birthplace of the gay rights movement. (Photo by Mario Tama/Getty Images)