Panmunjom North Korean soldiers cover the southern door of the building that crosses the demarcation line. They are literally standing in South Korea.
After staying here for a while you will be escorted out of the tent and the North Korean soldiers will leave too locking the Northern door (where you com in and out the building) and South Korean soldiers will enter. Then two of them will stand in front of the northern door. Please bear in mind that visitors are not allowed to step behind these soldiers.