Like others said, it's the "Family of the Day" and in my experience, it's usually a family traveling for the first time on the cruise and often have small children. They get to board first and get a little ching a ling announcement at port about "hey this is the family of the day"
We were told by our room service CM that we were family of the day on day 2 of our cruise and provided random room service deliveries like cookies and mickey bars - this happened on our first cruise so my guess is that it happens to only first time sailing families