So, why don't we see the downward slant as well in the Moorman photo?
It's because of what the Moorman photo is: a cookie-cutout of a larger photo taken by Babushka Lady. And BL shot at a diagonal. And what happens when you shoot at a diagonal? You capture a larger field.
So, when I say that the Moorman photo was taken by Babushka Lady, I don't mean that it is the entire image that BL took. It's a crop of it. And once you start cropping, you lose your bearing to the ground, and you can turn the crop any which way you want.