Let’s say that you’re speaking to a group of ten people, and one chair is empty. Why should you remove it?
Imagine trying to contain water in a sieve. You can’t.
That’s what happens when you try to contain energy in a room with empty seats. The empty seats convey: “People are missing. People didn’t show up. We’re waiting for them. Oh-oh, they’re still not here.” It’s distracting.
Remove those empty chairs, and explain why: “I’d like to create a space where our energy can percolate. Let’s remove these distractions.”