I'm afraid that this product is exactly what it looks like: a bracket that holds a stringed plastic bag while attached to your dog's tail. At the expense of your dog's sense of dignity, you get to avoid scooping up after him:
People invented many useful technologies to make people's life easier. All these inventions (car is among one of them) are to make people's life more convenient. With our "PooTrap", no need to worry that dogs will cause environment pollution, and as dogs owners may know, actually it's difficult to pick up poop.
Link via CrunchGear (where there is a video)