The Polaroids
In the film, the batch of Polaroids are Objects.
This means that they were in the room at the time of the Event.
So, how could pictures (clues) of the Vault, which was set up later by a Collector to store other Objects, have already been taken? The Vault was set up after the Event, so pictures leading to it could not have been Objects. QED.
Any ideas?
I greatly enjoyed the movie.