A girl performs martial arts during a function to mark International Women's Day at a school in Hyderabad, India, on March 7, 2014. (Photo by Mahesh Kumar A./Associated Press)

Two years ago, Mark Rober was an engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California, part of a team that worked on the Curiosity rover. For Halloween, he strapped an iPad to his chest and another to his back. Then he turned them on and used the devices’ cameras and screens to make it appear as if he had a gaping hole in the middle of his torso. (Photo By Mark Rober)

Vietnamese female commissioned officers of the signal force march during a parade marking their 70th National Day at Ba Dinh square in Hanoi, Vietnam September 2, 2015. (Photo by Reuters/Kham)

Monaco's Princess Charlotte Casiraghi arrives to attend a mass at the Saint Nicholas Cathedral during the celebrations marking Monaco's National Day, on November 19, 2016 in Monaco. (Photo by Valery Hache/Reuters)

A reveler participates in a parade on the streets during a carnival to mark the annual Orthodox St. Vasilij Day in the village of Vevcani, south of the Macedonian capital of Skopje, January 13, 2017. (Photo by Ognen Teofilovski/Reuters)

A member of a winter swimming club wears flippers during the celebration of Maslenitsa, also known as Pancake Week, a pagan holiday, marking the end of the winter, in Novosibirsk, Russia. (Photo by Alexandr Kryazhev/Sputnik/Profimedia)

The Duchess of Cambridge joins Family Action at a Christmas Tree Farm to mark her new patronage, in Great Missenden, Buckinghamshire, UK, on the 4th December 2019. (Photo by James Whatling/The Mega Agency)

A large brawl breaks out as people leave the track after Sydney Racing at Rosehill Gardens on December 07, 2019 in Sydney, Australia. (Photo by Mark Evans/Getty Images)