My idea is simple. Every product essentially have different optimal storing temperatures. So why do we cool everything in a box that treats everything the same. A smart refrigerator should only cool products as much as needed. Therefore my idea is to invent a differentiated cooling refrigerator.
So the idea is that you cool milk at the milk storing temperature. Ketchup at the ketchup storing temperature and so on. The purpose of this not to waste energy on unnecessary cooling.