I have studied Lang's photo for about ten minutes, and I still don't understand the shadows. I see a shadow from the open upward door next to a shadow of some kind of dome on the top of the airplane. However, there is another dimmer shadow over much of the top of the fuselage that seems to be from the edge of the tail nearly directly lined up horizontally with the direction of the sun. There is also a shadow on the top of the left wing which seems to be from the rear stabilizer fin and it is nearly directly lined up vertically with the sun. This double alignment is an odd coincidence, but not impossible.
What I don't understand is the dark shadow of the dome lying inside the dimmer shadow of the tail. Unless there two sources of light, it is not possible to have both a dim shadow and a dark shadow at the same time in the same place.