A commercial edifice created by taking a large piece of glossy cardboard, cutting a slot down the center of the lower portion, then sliding in a second, discreetly-sized piece of cardboard perpendicular to the first. If done correctly, this will form a free-standing structure.
Most commonly, standees are made to look like life-size, two-dimensional replicas of famous people. They're typically created as part of a promo campaign for the product the celebrity is endorsing, or sold as a collector's item at novelty stores.
A classic mallrat prank is to abduct a standee from a store display, shoot off a roll of pictures of it posed in rather unlikely places, get them developed at the one-hour photo shop and then returning both the standee and the pictures back to the original location. Mostly a variation on the lawn gnome prank, but with the added challenge of having to evade mall security while doing it.