According to this article,
In order to get the authentic look of POWs, Angelina put stars Jack
O'Connell, Garrett Hedlund and Finn Wittrock on strict 700-calorie
diets. While the dietary challenge presented obstacles, Angelina
expressed her gratitude in a way that made it all worth it.
"The funny thing is we'd all be on set and everybody's kind ...
Here is an explanation:
But then everything is interrupted as an American bomber plane flies overhead and in Morse code tells them that the war is over. All the POWs cheer.
So whatever the pilot did, was Morse code, and a lot of people back then, especially in the war, knew Morse code, and were able to decipher it when they saw or heard it.
If the Japanese are the ones running the game, a game that involves shooting the looser, it's not a game, it's a punishment or lesson. They let the rest watch so they learn that either you do what you are told, or you will be killed.
Public humiliation and punishments are a common tactic in keeping prisoners demoralized and compliant.
This link seems to say that it's CGI
Today, Christian Bale wouldn't need to drop a deadly 63 pounds for The Machinist. Digital retouching can take the physical element out of preparing for a role. For example, Jack O'Connell was saved from having to lose all the weight necessary to play a Nazi concentration camp prisoner in the Angelina Jolie-directed ...