Here's a close up. I don't read Chinese, but the picture shows Stalin, pushing Mao, pushing a Chinese soldier into the fire - so I'm guessing it's saying something like "You don't want to be Stalin's pawn, do you?"
They also had an entire room dedicated to American and South Korean created propaganda that was used to try to convince the Chinese and North Korean troops to surrender.
As museum moved into the era of modern warfare, they had an entire room dedicated to English-language propaganda written by the Chinese and the North Koreans to convince American forces to surrender.