At Impact Fix(Impact position)...the back of the "Flat Left Wrist" ideally should face down the Angle of Approach, or a little to right field. At Address, or if you set up with the hands centered, the bent left hand will point more parallel with the Base Line, or Target Line. This is with the Strong Single Action grip.
If you use a Stronger left hand grip, which some hitters do... the back of of left hand will point a little more to right field in both positions(Fix and Address).