Great question!! The hint to your question is the last sentence of the instructions. When we use the "show" logic, it allows new line items added subsequently to be added to your saved view. If you "select items to show" and a save a view, then new line items will not appear. So, as you progress in L2 you eventually will be adding more line items and by using "Show" those line items will automatically appear in your saved view.
Hope that helps.
Oh, you can add the line item to capture the "ITEM" by creating list formatted line item and using the ITEM() Function.