And it was reported on the official blog that a few days ago, the staff went to a wrecking yard to gather materials for the movie. The image shows an assistant taking pictures of a mountain of scrap iron.
First thing that came to mind: The novel version of this scene takes place in a garbage dump (with Kamina appearing on top of a dust box instead of Nia's box). And Nakashima wrote in the afterword that the new scenes in the middle section of the 4th novel are discarded ideas from the first draft of the scenario for Lagann-hen. So...could they be remaking the alternate universe sequence for the movie? Is that why they went to the wrecking yard? To take reference shots?
Or maybe it's something else entirely, but that's all I can think of. :\