Continuity mistake: When Klink sits down with Marlene, her hands alternate between being on his face to behind his neck and back between shots.
Continuity mistake: As Schultz marches in with the Kraut platoon, he reports to Klink. As he goes to stand at attention and report, the new tunnel section he's over collapses, and he completely disappears into the hole. The camera goes to a close up on Klink, then back to the hole, and you see Schultz standing in the hole and it's only chest deep.
Answer: It's a solitary cell. Steve McQueen, star of 'The Great Escape' is known as the 'Cooler King'.