From Coolhunting.com: 

“For the next three weekends, squeezed between NYC’s omnipresent hot dog and gyro stands, you’ll find one vendor hawking a very different product. In collaboration with Scandinavian clothing and design store [hus], Tretorn will sell their wellies, sneakers, accessories and apparel from a custom built ‘Wellie Wagon’”

You know, because it’s not really superfluous if it’s an event. 

Tretorn Wellie Wagon