In the opening scene - in the boxing ring - there are stools (for the boxers to use between rounds) set up in adjacent corners. In a real match, the stools would be in opposite corners.
The Iceman who is so good nobody has ever seen him doesn't bother obscuring his face or blindfolding or eliminating the people in the sky box he takes over. He binds and gags them, but otherwise leaves them conscious and free to ogle while he prepares to take out his one assigned target.
For being in the middle of a major prize fight there are a lot of people milling about in the concourse. It's more likely that everyone would be in their seats during the main event.