I'm pretty sure I don't walk past a no photography allowed sign at the door, so tough tits. I often take a photo of the label with the price and the name of the thing as I'm taking it into consideration. It's called shopping around. As far as I'm concerned, retailers should be bloody well glad that I'm even standing in their store because recently they are overcharging more, discounting less, and not getting stock in that they have advertised. If I want to take a photo so I can think about my decision I will do so.