Okay kiddo, so you know how some houses are really big and fancy? Those are called mansions. Sometimes people want to make their house into a mansion too, so they add a lot of extra rooms and space to it.
But sometimes, when people do this, it makes their house look really big and out of place compared to all the other houses around it. That's what we call mansionization - when a house is made much bigger and fancier than all the other houses in the neighborhood.
People might not like mansionization because it can make their neighborhood look different and less cozy. So sometimes, cities and towns make rules to stop people from making their houses too big and fancy - kind of like how a teacher might make rules to keep everyone in the class behaving nicely.
Does that make sense, kiddo?