Trolling IKEA

In Adage: We have an Ikea store nearby.  The number of items they have is so large that it is hard to believe anyone can recognize one that is out of place.  So a design agency surreptitiously placed a product there in the right context, and watched what happened. Includes Video.  Probably illegal or at least unethical,  or do they need to place a sign at the entrance saying that  non Ikea products cannot be placed on the shelves?  Have to admire the sheer creativity.