A lot of golfers don't understand the position of their hands and their club at the top of the swing, where it should be and how it affects their ballflight. Ideally, your golf club is on a plane where your left arm, left wrist and clubface are all on the same plane at the top. Anything that is short of parallel at the top should point just a little bit to the left.
What is the Correct Club Position in a Backswing?
This golf club is laid off, it is laid off my arm, and that is a position that you would see players in who have a tendency to leave the face open and slice to the right. This golf club is considered across the line, it is across the line of my arms and that club will tend to hit too much from the inside and the golfer would tend to hook the golf ball.
So ideally your left arm, left wrist and clubface should be on the same plane on the top. Now if your clubface is not matching your arm at the top of the swing it could be your wrist position is too cupped or bowed, or it could be a change in your grip.
If your grip is too weak it could look like that, where the clubface is facing toe down. If it is too strong it could be like this, where it is facing skyward in a closed position. You want the left arm, the left wrist and the clubface all in the same plane at the top and that is the plane that gives you the best chance of being square at impact.