Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

Claire McGuire (C) smiles after winning the women's snowboard division of the Bikini & Board Shorts Downhill at Crystal Mountain, a ski resort near Enumclaw, Washington April 19, 2014. Skiers and snowboarders competed for a chance to win one of four season's passes. (Photo by David Ryder/Reuters)

Arizona Cardinals cheerleader Claire Thorton, center, smiles as Air Force Capt. Eric Straub proposes to her during the first half of an NFL football game against the Washington Redskins, Sunday, October 12, 2014, in Glendale, Ariz. Thorton accepted the proposal. (Photo by Rick Scuteri/AP Photo)

“Show Time”. It's a normal behavior of mantis. They're doing defence. When they're afraid of; raising their arms and spreading their wings. They looks like smiling dancer. Photo location: Nicosia, Cyprus. (Photo and caption by Hasan Baglar/National Geographic Photo Contest)

Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

One happy reveller smiled and gave a thumbs up to the camera in Newcastle, United Kingdom after receiving their A Level results on Tuesday, August 10, 2021. Students hit the town across the country, downing cocktails and letting their hair down after two years of studying during the pandemic. (Photo by Newcastle New Projects)

A South Korea fan smiles ahead of the Qatar 2022 World Cup Group H football match between Uruguay and South Korea at the Education City Stadium in Al-Rayyan, west of Doha on November 24, 2022. (Photo by Jewel Samad/AFP Photo)

U.S. First Lady Melania Trump smiles as she holds a football thrown to her by U.S. President Donald Trump during his joint news conference with Russia's President Vladimir Putin after a meeting in Helsinki, Finland, July 16, 2018. (Photo by Kevin Lamarque/Reuters)