Nesting Cups

So Paul and I were laying next to Izzy while she was "reading books" and jabbering to herself. After she was finished she went to the stacking cups which were built in a tower for her. She proceeded to start at the top and take one off at a time and put it down, take the next one off and stack on top of the one she has just taken off, etc until she had just nested smallest to biggest. We were shocked.