I'm guessing the flowers always tilt towards the west, where they get more light, so I had a hard time finding anything showing the inside, but here's one. I'm sure the tree is sterile (thank god, I can't imagine also cleaning up seeds from it!).
My neighbor across the street has a different type of white magnolia, their tree is about 1/3 of the size of mine.
Does anyone know what the tree in the lower right corner of the 2nd photo with white flowers is by chance? It's only about 12' tall now, but I saw a huge old one recently that had such a perfectly beautiful shape to it, it made me wonder what it was.