I would argue that unless you knew what specific item you were looking for, you wouldn't see anything inside any of them. Especially in the case of the HHH, you have to reach for a specific item and it is always on top. Like a bag of holding, turning a HHH inside out would cause all its contents to pour out, as it's fixed weight is appropriate to a leather pack, it should take considerable suspicion to risk damaging a customer's well-made leather pack by turning it inside out. As absolutely would happen to the side pouches for a normally constructed pack matching the item description. Or is there a permanent<em>detect magic </em>effect in place?