It is important to start by realising that this excellent short story is written in the third person limited point of view, as we follow the thoughts and actions of one character, George Hadley. Thus it is that we have access to his thoughts and feelings, but are only able to "hear" the speech of other characters. Thus it is that the unaware George Hadley, ignorant of what he is doing to his children, brings in David McClean to help analyse the situation and the problems of his children. The narrative voice thus uses David McClean's speech to provide valuable social commentary on the situation that the Hadleys are facing, but more generally, upon the impact of giving children the kind of unrestricted access to technology without careful boundaries. Consider what David McClean says to George Hadley about the mistakes he had made:
You've let this room and this house replace you and your wife in your children's affections. This room is their mother and father, far more important in their lives than their real parents.
Thus the narrative voice, in presenting the speech of David McClean, acts to present the important message and warning that the story contains. Unrestricted access without boundaries to an ever-more sophisticated technology can have unexepcted and devastating social impact, as technology can become more important to children than traditional concepts such as family and community. This is of course a social commentary that we need to heed particularly in our day and age.