Is it on the trolley?

For a while now Bronwyn and Frog have been playing a game when they're covering on the enquiry desk in Lending. I've noticed them scoring points but hadn't sussed the game until Bronwyn explained it to me. The aim of the game is to see how often you can legitimately say to customers:

"Is it on the trolley? Can you point to it?"

à la Julie Waters in the old "Victoria Wood on TV" sketch.

Given how often kids go to the desk saying: "I want the book my friend just brought in" the score lines can get into cricket match proportions.