Why would you have your dog wear a anti-pulling thing when not using it? And why is it pulled closed when not in use? That's only supposed to happen when a dog pulls on the leash, which isn't even attached.
Since he's in a store and considering the picture on his harness, is she claiming he's a service dog? Aren't service dogs supposed to be trained well? If so it shouldn't need a anti-pulling thing.
Poor dog looks a bit uncomfortable too... Hope it's just the dog version of an unfortunate picture making him look like that.