To begin with, this is not how batting coaches coach batters to hit. It is, however, a down-n-dirty way to place the ball in play for reasons other than body placement, feet placement, and a ton of other stuff.
So, get yourself a batting T, put a ball on it, then hold your bat by moving the top hand only and watch where the ball goes. Hence:, for a right-handed batter …
For a left handed batter, the top hand turns the same, but the ball will go just the opposite way.
Remember to turn your upper hand only, slightly, and keep it in place while you swing at the pitch.
A batter who has a sore shoulder, has just been nailed in the leading arm or hip with a wild pitch, has a sore back, stiff neck, or other body issues, will find this upper hand placement technique really works. Just be mindful that this hand posture won’t have you reaching the lights, but you will place the ball more often than not in the direction that you want - even with variation of the swipe path of the bat.