The "Housekeeping" portion of your Introduction establishes you as the leader of your professional presentation.
As children, we learn that the person giving instruction at the front of the room is the leader. It is ingrained in our minds from that tender age that we should be giving our attention to that person. At a certain point, we do it almost innately.
As adults we know that, although that neural pathway to the room leader still exists, we need to do a bit more. A great way to establish yourself as the leader of the proceedings is to include a "housekeeping" section in your presentation introduction. Not only will you manage your audience's expectations for the day, but you'll also send the message that you'll be leading everyone along.
Here's an infographic reminder about how you can keep your house in order like a leader: