1. It is always useful to rotate the view. Your eye is often more "clever" than yourself. You'll find that the photograph was taken from front above. You can tell it also by looking at the houses below, what walls you see and what you don't. So, the image is not from directly above.

2. I don't think they fly that Lanc very high. Nor do the remaining B-17s. It's no idea to climb to old operational altitudes. The measure tool gives a wingspan of 50,5 meters when it really is 31 meters. About 63 percent too much. Perhaps some mathematician will calculate the altitude. Lancaster's service ceiling was 8,160 m, B-24 had about the same (8,500 m) and B-17 considerably more (10,850 m). I think that 8th Air Force just took the burden of daylight operations. Also the Lancasters flew high at nights.

This is my explanation for the missing shadow:

This is an aerial photograph and the sun is shining from behind, about SSW. The plane is flying north, so the shadow should be in front of it. From these "dirty cases" we have found that the photographing plane is flying on a north-south course. Maybe it is the case with this image too and the photo was taken on the southward leg of the photoplane. The two planes had opposite courses and the shadow did not get in the first (northern) frame but the Lanc itself did make it in the next (southern) frame.

A reverse to this can be seen in Heathrow 09L. There the photoplane flew from west to east and got a landing Air France Airbus in four consecutive frames.