We don't need a new federal law, or new government agency to deal with this. If some individual has been victimized by misleading products let them sue and justify damages in a court of law. We don't need statutory limitations placed on photoshopping, nanny government deciding how much is too much before there is even a complaint... nor do we need the foreseen swat team raids on retouching artists.
Most Ansel Adams photography prints involved lots of manipulation in the darkroom after the image was taken. Photoshop is the modern darkroom. But it is a much more powerful tool.