Nice example of corporate flash-mobbing

T-Mobile Dance
I don’t know if you have seen this commercial/event executed for T-Mobile in January in Liverpool.
It is a commercial version of the phenom typically called Flash-Mobbing.
Quite the production, but well executed. And, personally, it feels good to watch a few times.
There are a few versions on YouTube, also a couple of videos from behind the scenes in production.
Anyone know the agency and production company?