Members of Japan's idol group “Virtual Currency Girls” wearing cryptocurrency-themed masks perform in their debut stage in Tokyo, Japan, January 12, 2018. Japanese female idols have teamed up to form the ‘Virtual Currency Girls’ group to promote the knowledge of cryptocurrencies through entertainment. Each of its 8 members represents a cryptocurrency: bitcoin cash, bitcoin, ether, neo, nem, ripple, mona, and cardano. (Photo by Kim Kyung-Hoon/Reuters)

A fireman from the London Fire Brigade, wearing a smoke helmet. (Photo by Topical Press Agency/Getty Images). Circa 1908

A close up of a Khon mask July 8, 2011 in Angthong, Thailand. The paper mache Khon masks, are part of the ornate glittering costumes used in the stylized classical Thai dance form known as Khon. (Photo by Paula Bronstein/Getty Images)

Women compare their bikini marks after sunbathing on a terrace to have the perfect bikini line (“marquinha” in Portuguese), at the Erika Bronze spa in Rio de Janeiro, Brazil, November 17, 2016. Women start arriving at the spa between 7am and 8am and will tan for approximately 3 hours. (Photo by Pilar Olivares/Reuters)

Members of Japanese idol group Kamen Joshi (Masked Girls) in attires featuring images or names of U.S. President-elect Donald Trump, pose for a photo after their concert at their theatre in Tokyo's Akihabara district, Japan, December 12, 2016. (Photo by Toru Hanai/Reuters)

A Pablo Picasso papier mache “huge head” mask, known as “Capgros” in Catalan, is displayed at the entrance of the “El Ingenio” shop on August 23, 2011 in Barcelona, Spain. “El Ingenio” (The Ingenuity) has been making and selling papier mache giant masks and huge heads for Catalan popular festivals since 1838. The “La Merce” festival will be held on September 24 to observe the feast day of Our Lady of Mercy, patron saint of Barcelona. (Photo by David Ramos/Getty Images)