Just because the president of the United States is the leader of the country's executive branch doesn't mean that the whole presidential family can do whatever they want. In fact, there's a whole list of things the first family is supposed to do - and a list of things they shouldn't do - regardless of whether they'd actually like to do them or not.
Some of these are surprisingly strict rules for the first family, like how opening White House windows is expressly forbidden. This is one of the stranger things that show what it's like to live in the White House. Some rules are more like guidelines for the president and their family, such as various holiday events. The first family also has to be keenly aware of all the priceless artwork in the White House, which can be difficult if you're one of the presidents with problem children. All in all, these first family traditions show how they don't just make the rules - they have to follow some too.