The hole is exactly for what you think it is for - but you have no point of reference quite often. It is hard to see where the ball of light is going. So you use your fingers in a V to get a reference / starting point / secondary aiming device to get you started.
This allows you to put your fingers (who have a little light on them) around the object you are trying to signal, then you drop the ball of light on it, and you can, at that point, take away your fingers.
Try this - go out into your back yard - and try to put the ball of light on a distant object (say a far off water tower) what you will find is that if the object is small, it is hard to get started. The V help tremendously.
TF