This first one is out of sight. Comparative advantage can be a difficult concept to teach and this is a wonderful example. Two entities each have a comparative advantage in one product (fun or happy) and when the two specialize and engage in trade they are both able to achieve higher levels of fun AND happy than they would be able to on their own.
The second uses the production possibilities curve, which is an easy visualization showing all possible production combinations along the curve. Anything inside the curve shows resources being underutilized or ineffecient production. Anything outside the curve is, well, as it states, impossible. :)
Enjoy a happy Valentine's day!