Board Thread:General Discussion/@comment-4224349-20150319205546/@comment-5391523-20150320151744

It's likely that the room was used to create hypothetical scenarios, since Rose is the leader and was, foremost, the strategist, she used it to unleash her best/worst case scenarios during battles. It'd also be a plot twist if many things we've seen in the show were granted by Garnet's future vision and Rose's hypothetical room (of course that is, obviously, not the case, but certainly will be in upcoming episodes). I'm eager to see what Rose had left before him and what happened during her battle against that Diamond-like gem.