I see two white objects ( I have roughly outlined in yellow ) and two shadows ( outlined in blue ) . One of the white objects could be the fuselage of an airliner , and there are gradations in the degree of whiteness from nose to rearward which could be windows ( green ). The second , smaller white object to the left , could be the right wing engine .
I could imagine the wings being sheared off at impact , folded back along the fuselage , pulverized , and the wing tank contents sprayed into an aerosol which would be ignited in a flash by the heat generated during impact .
The problem I have with that scenario , is that the wreckage of a jet engine is recognizable in a photo I saw of the interior of the Pentagon . I find it hard to believe an engine would be recognizable after impact with a stone or concrete building at around 500 mph . And why just one engine ?