You are right. I don't know why I didn't in the first place.... I suppose because I always think that a photo born square should have all the attributes of squareness: centre-framed, large aperture and space at the back to highlight the subject.... And then I started looking at her hands and eyes... And I wasn't that convinced anymore....
Yes this does look better, and I agree with you in that I don't usually crop much and leave the square as a square. About to post a shot of Lauren where I have cropped my square...must be catching!
I think one of the reasons for this cropped version appearing better is that in the un-cropped version it almost looks like the breast is part of the arm that goes up to the face.Which would probably require that your model have three arms.