Registered to report this one.
Very surprising it was possible, as it would have to have been animated lol
Unless it's an easter egg of sorts.
Basically, the images will explain it, but what's happening is:
Train docked to collect cargo, and instead of a cargo container/nothing being added to the train (cargo car already had a load) The crane picked up the "building" and loaded it back and forth.
P.S. Please ignore the cheating XD