Here's what they said.
"In Vietnam during the war," said the guy at the door with a scowl, "American troops thought they were being welcomed happily because everyone was smiling. But a smile means something different in Vietnam. Sometimes it's an expression of fear. 'Hey, I'm smiling, chill out, please don't kill me.' In Vietnam, people smile when they're not sure how to react."
"Can you provide a URL to back that up?"
"Maybe later," he said modestly, ignoring my question, "We're taking that further. We're rewiring every facial expression." He looked curious for a second. "Inside these walls, we've got a different set of emotional meanings for every expression. We immerse ourselves in it."
"Uh, okay," I mumbled. "Why?"
"No, not like that," he added, eyes wide with fear, "You gave me a cue last time."
I had the feeling that we weren't really communicating well.
"Now get out," he said with a broad, ingratiating smile.