Alnus Rubra
Loving nature’s wonders
It's an illusion. I just measured them on the screen and they're precisely the same. I blew it up so from string center to string center both gaps measured 39/64". The D-G is the same.
I don’t think that the OP took the photo absolutely head on, as you can see the right hand side of the neck.
See the OP’s photo that I edited in upright position and it’s even more obvious.