The principal adds more details to the example of a way to make learning fun.
The whole excerpt above is about how Mrs. Smith, the teacher, makes learning fun. The excerpt mentions nothing of Mrs. Smith being dramatic or inspiring. The description of the hats is not necessarily a story, it is a mere statement giving evidence/example. It doesn't introduce the teacher either. The principal introduces the teacher by stating that she has a way of making learning fun.
Hope this helps!
