Way to communicate contempt for your customers. If you're in the business of selling decorative replicas of cartoon swords, you need to be in on the kayfabe. Nobody is expecting to take one of these to a real swordfight. What they are expecting, however, is to have a cool prop to show their friends, and it's not unreasonable to expect the cool prop to feel like it's not trying to fly across the yard if you swing it around.
If you don't want people to touch the merchandise, the second sign is all you need.
