I was actually about to say that. And that was the cool thing for me. From watching the Firefly DVDs, I learned that they had an upstairs and a downstairs set. The first time I watched Serenity, I knew they had to recreate the set for the movie, and at that part where Simon follows Mal downstairs, the wipe completely fooled me, and I thought, "Wow, were they able to do a two-story set for this movie?" It was only when I watched the commentary, and Joss pointed out the wipe that I ever noticed it.