When I was playing in the tourney last weekend in Oklahoma City, in one of my matches my opponent kept getting upset and annoyed at people walking by.
I have always been somewhat amused by this.
The reason why is because that means my opponent is letting things get to them. It means they are not completely focusing on the game at hand.
Don't get me wrong - you don't want to be distracted or have people walking by interfere with your shot, but to get visibly angry and annoyed is not the answer. To give the person mean looks or to shout at them is not the answer. I see it as they are just upsetting themselves.
Just get back up, get ready to re-shoot the shot.
When I see an opponent upset, I know I have an advantage. They are letting things bother them and getting distracted. Of course, if they are losing in the match, then we all know they would be getting even more upset than usual anyway. So, someone walking by just escalates the fact they are losing. I've even seen someone yell at people walking by when she was the one who wasn't even AT the table shooting, she was so fuming about it.
And I remember CLEARLY back in 1999 I was playing in a ladies tournament in Florida. They had one open table and it was near the bathroom. The tournament director warned me it was close to the bathroom and be distracting with everyone walking by. I exclaimed, "put me on that table, I'm ready!" because I already knew my opponent would get upset about it (she has a history of getting irritated with things like this), and I would have the advantage. Yep, I won the match.
It seems only certain players get super agitated over people walking by. Others seem to take it in stride. I suggest if you are this player to accept the conditions around you and don't let them upset you. That /will/ affect your game. You want calmness in your mind and not to be distracted with feelings of upsetness.