Well, let's teach children the concept of post-modernism using the Sesame Street characters (or more correctly Jim Henson's Muppets). Basically Ernie is attempting to paint a picture of his neighbourhood but everybody is throwing in their own thoughts. Oscar hates it because, well, he's Oscar, and everybody else is coming along to give him some pointers. In the end Big Bird clumsily crashes into everybody apparently destroying the painting, until Oscar pokes his head out of his trashcan to say that it is the most magnificent piece of artwork he has ever seen.
This story is about opinions and perceptions and how they change from person to person. Ernie starts off by noting that the street looks different based upon how he is looking at it, so while the reality of the street may not change, the perception of the street will (though not to Oscar, because Oscar only sees the street in his own way). Others who come along all have their own opinion on how the painting will look good, and it is only when the painting is apparently destroyed (through an act of chaos) that the true beauty of the painting (at least in the eye of one beholder) is seen.
Some might suggest that post-modernism is too complicated to teach to children, but the author seems to do an okay job here. Others may say that it is not the writer's intention to write a post-modernist text, however once again I point to this book and suggest that what the book is saying is what is being said to me, who interprets this book as a post-modernist text. Ernie never set out to create a post-modern painting, but that is what he creates in the end, and it is Oscar who sees the beauty of that painting, where as everybody else sees something that might as well go into the garbage bin (where is ends up anyway).