Imagine you have a big bag of your favorite candy. You keep adding more candy to the bag until it is completely stuffed and no more candy can fit inside. This is called being "saturated" - it means there is no more room for anything else.
In the same way, a cone can become "cone-saturated" when it is completely filled with something, like ice cream or popcorn. A cone that is not "cone-saturated" may have some empty space left at the bottom, but a "cone-saturated" cone has no room for anything else. It's completely full!