Earlier quoted context omitted.
I've read that in feng shui what you describe is called the "command position". I'm not able to work with my back to a crowd. That's a recipe for anxiety. I quit a company when they moved my desk so my back was to a hallway, and refused to compromise on this issue in any way.
If it happens again, I've been told that having a mirror on your desk so that you can see what's going on behind you can help a lot.
She would audibly be surprised and distract others.