To apply double-pushout approach from interaction point of view, we need to figure out all basic actions that are implicitly declared within the abstract relationships in the diagram. In addition, partial order constrains must be specified for the actions with causal dependency.
The typical scenario at an online store is the whole process to deal with customer orders. The Customer could place orders with the company. And the company will search through the stores for availability. If the order is available, the company will let the store deliver the order to the customer.