Great Britain’s team is using a very fitting celebration at the World Baseball Classic.
The Great Britain team is filled with many American and Bahamas players, and very few British-born players. So their celebration after big plays is something that somewhat mocks the British.
The players are pretending to sip a cup of tea:

https://twitter.com/MLBONFOX/status/1635387713523253249
Tea is synonymous with British culture, which explains the celebration.
Great Britain lost to the U.S. 6-2 on Saturday in Group C play at the WBC. They were hammered by Canada 18-8 on Sunday. On Monday, they were facing Colombia and doing the celebration during the game.