Explanation
The thing that they should do to add the missing information to the custom Contact list view is to select Fields to Display. Fields to Display is an option that allows the user to customize which columns appear in the list view, based on the fields that are associated with the object. The user can access the Fields to Display option by clicking on the List View Controls menu and then clicking on Select Fields to Display. There, they can add, remove, and reorder the fields that they want to see in the list view. Editing sharing settings or editing list filters are not the correct actions to add the missing information to the list view, because they affect the visibility and the criteria of the records, not the columns.