I'm amazed to look at how a very little change in the angle of the camera can have such a profound effect on the shape of the church. You can see that assembling these images into one coherent image will not be a trivial task.

You should also note, that if I were to overlay the images in the best (thought rough) orientation and location, that your eye-brain system would be able to assemble the church with little difficulty.

It makes me give NASA a hell of a lot more credit. But then, they've been assembling digital mosaics for decades now, and the military for even longer. I'm sure they've got some neat tricks up their sleeves.