Big Bird lures Maria to his nest to show her the snowman he's built. Maria says that it's upside down and that he should have looked at a picture of a snowman to see what one looks like. Big Bird produces a book called "World's Great Snowmen" and says it looks just alike a picture in the book - which Maria notes is upside down. She offers to help fix it, placing the head on the top, etc. Big Bird says he liked it better his first way, and Maria assures him that's fine: he's invented a new way to build a snowman. What Do You Do With a Pet? (thetvdb.com)