They certainly picked a proper name. It's not a place where you can sit and drink you smoothie; it's a box :) No really, it measures about 3x3 meters.
You go in, stand in line (there's almost always a line - that means something), order, wait a minute or 2, and walk out with a delicious drink.
There are a couple of vegan options (juices and soy smoothies), all yummy.
Tip: While you are waiting, you can watch people eat crappy fast food from a food-in-the-wall joint across the hallway and feel even better about yourself since you're going for the healthy option ;) .