Hmmm....I assume you mean when they were moving between the 'old' and 'our' side. It was very well done between the B&W and colour scenes. I expect it would have been better in 3D.
We went to see a 10.15 am show. We waited and waited and waited and nothing happened. And then at 10.45 am, someone came in to say they were having technical problems. They apologised and started handing out free tickets. One to replace the ticket we had bought; and one extra for the inconvenience. We headed out and got in line to get tickets for the 11.45 am show. We still have the "sorry for the inconvenience ticket" to go. We were planning on seeing The Hobbit II with that.
But I wonder if I can convince DS to go see Frozen again with me in 3D??