When Debbie gives Tina a cardboard piano, she is sure that Tina will love it. After all, Debbie spent a long time making it, and it looks just like a real piano. Now Tina can learn to play, too. It will be so amazing.
But just because you are friends with somebody, and just because you are the same in most ways, doesn't mean that you will always see eye to eye.
Friendship can be tricky. Really, really tricky. Even for true best friends. Even for Debbie and Tina.