I don't understand where this gap is? Is this what you mean?
Because if its where i think you mean, (the outside of the mirror, between it and the mirror glass, where i circled) then that has to be there. There has to be a gap for the mirror to move! That one just says the person was looking more down the side of the car, then the road/background.
The mirrors have to have a full 360* range of motion for different sizes of drivers, hence why the gap i circled is so big. This driver was looking more down the side of the car, then the road/background.
If its not there, then i apologize ahead of time.