cool things with wheels since 2006
That is complicated. It looks like they're going to jack it up and mount that on the nacelle of a 737. Taking to a dynamometer? I think the most likely is that it's used for engine installation, and all of that rigging is to lift the power module up into the chassis as delicately as possible.
Veyron assembly: it shows this dolly in the first minute of the video. https://www.youtube.com/watch?v=e0us0dVNZck