Shoppers at the Philadelphia Premium Outlets on Sunday might have been slightly taken aback to see someone stop in the middle of the concourse and start doing yoga stretches. They may have been more surprised still, perhaps, when a second "shopper" joined the spontaneous yoga with a series of dance moves.

By the time the strains of Martin Solveig's "Hello" were blaring at full volume through the outlets' PA system though, it was apparent that the outlet mall had become the scene of a "flash mob." About 20 dancers dressed in red tops performed a routine as shoppers stopped to watch.

The flash mob was orchestrated by the Moyo Yoga Studio in Skippack, which copped to the stunt on its Facebook page.

As is the way of flash mobs, the dancers dissolved into the shopping crowd at the conclusion of their routine. Watch the video, above, to see all the action.