What are the speakers talking about?

M: I have a question. I’m never quite sure where to sit during a business meeting.
W: The ancient Chinese art " Feng Shui" teaches that you should never sit with the door behind you—and actually there’s a scientific reason for that. When a person’s back is placed towards an open space he becomes stressed: his blood pressure increases and his heart beats faster.
M: That makes sense! People subconsciously worry about getting attacked if they don’t know what’s going on behind them.