It seems to correspond roughly to who has the power in a given conversation.

Tell:

Walter: I want to buy a pizza. It should have bread and cheese and pepperoni on it. Bring it to Address, and I'll give the delivery minion its cost, plus a tip if it is within time X.

Pizza Human: Alright.

Tell

Pizza Humans' piece of paper:

We offer boring pizzas (with just cheese and pepperoni) for $9. We offer other pizza with decent toppings X, Y and Z for $14. We have a family deal that comes with two pizzas and a free coke and garlic bread and home delivery for $20. If you don't get your pizzas within 45 minutes your order is free.

Walter: I'll order the family deal with pizzas 3 and 7. Address is ....

The interaction can be described either way just as comfortably. Of all the common forms of interaction this kind of exchange has among the least (relevant) power inequality. A market that is more or less efficient. In fact, a slight variation on your model may emphasise the importance not just of who has the power but to what degree there isa difference at all.