Hello, 

Well I guess this is just to insist on the background nature of those activities. You shouldn't be expecting user interactions at this point but mainly automatic processing.

I think

It means that, whenever you provide an activity in the actions, it executes automatically by Procom agent as soon as it reaches the specified Goal or Deadline time.

As the agent runs periodically, we need to perform any manual actions to execute the activity.

These are background activities and when they run no user interaction is expected to be performed.