I was the one who created the model. I would like to say for the record, and to clear up any confusion. It is purely representational of how the mechanism could work, and not of a final product. We expect that if this is accurate, it will be in the dark, and accompanied by many disorientating special/scare effects.
The drum was purely for effect, and has no inclusion in the mechanism. But I did consider it as a possibility, given the hypnosis theme that seems to be emerging. If you look a bit closer, you will see the track in the model is attached to two rings, which I believe will be rotated in a very similar way to a trommel.
I also do not believe that the trick track will be below the shop, but below the maintenance bay at ground level, before joining the lift hill. I do however believe the ride will pass below the shop after a steep drop.