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)

Souvenirs seller smiles during the street market of the “2021 Agrorus” international agricultural fair at the Expoforum exhibition centre in St. Petersburg, Russia, 02 September 2021. The Exhibition opens for visitors until 05 September 2021. (Photo by Anatoly Maltsev/EPA/EFE)

Stanford golfer Rose Shang smiles towards her teammates after winning the NCAA college women's golf championship at Grayhawk Golf Club, Monday, May 22, 2023, in Scottsdale, Ariz. (Photo by Matt York/AP Photo)

These girls are all smiles as they celebrate surviving A-level results day in Birmingham, England on August 15, 2019. The A Level is a subject-based qualification conferred as part of the General Certificate of Education, as well as a school leaving qualification offered by the educational bodies in the United Kingdom. (Photo by SnapperSK/SnapperMS)

A tourist walks inside the Ice Palace glacier hollow at Hintertux glacier, located at around 3250 meters above sea level, in Zillertal, Austria, 02 March, 2016. The hollow's temperature remains constant at 0 degrees Celsius, in summer and winter alike, and is also used by the University of Innsbruck for scientific research projects. (Photo by Lisi Niesner/EPA)

A frog appears to have a big smile for the camera, Russia. Things are heating up at the Comedy Wildlife Photography Awards as the shortlisted final 40 entries are revealed. This year's competition has featured over 2200 hilarious entries from around the world with photos including a fox face planting in the snow, a dancing brown bear and a pair of seemingly headless penguins – all beautifully photographed with perfect comedy timing and a strong conservation message. (Photo by Artyom Krivosheev/Barcroft Images/Comedy Wildlife Photography Awards 2016)

An Indian girl smiles under a water splash at a water park as the temperatures reached 38 degree Celsius in Calcutta, eastern India, 12 June 2016. The summer or pre-monsoon season lasts from March to July in eastern India with the highest day temperatures ranging from 38 to 45 degrees Celsius. (Photo by Piyal Adhikary/EPA)

A billboard for JELL-O stands at the corner of Grand Street and West Broadway on August 2, 2011 in New York City. The billboard acts as a mood-meter by analyzing Twitter and guaging the number of happy and sad emoticons used at any given moment, causing the billboard's face to change between a smile and a frown. (Photo by Andrew Burton/Getty Images)