For use case 2, the scenario is triggered by the slot making a request for content (it’s an active slot). The content delivered will be based on the current state of the application, in this case the customer’s profile (his net worth). Because the customer is the main subject of the scenario, you make the slot customer-aware by selecting External Profile. You use Add Item to Slot in the scenario because the entire scenario is about the customer: the customer is the main subject of the scenario and the content that is delivered is specific to the customer. You create this scenario on the external cluster, but the scenario must be communicated to the internal cluster via the ProcessUpdateService. See Understanding Internal and External Profiles for more details.
(Note, this is opposite use case 1 where you have to use Add Item to Slot for Customer in which the subject of the scenario is not the customer, but the content is for the customer, you must use Add Item to Slot for Customer).
