Mutual Trust

The photo is from a supermarket and says something like:
To preserve mutual trust please open your bag! Thank You!

How an Earth is this going to build mutual trust between the store and the consumer? So I show you what is inside my bag and then you can trust me? WAIT A SECOND!? And how does this help me to trust the store?! I mean it's obvious that they don't trust me...

So am I allowed to ask the store to show me the statistics of their profits for the products? I'd like to know just for mutual trust. I mean I just want to know that they are not ripping me of.

ARGH! (Obvious to say that I've never shown them what's inside my bag.)