Our narrator of this adorable tale wants a pet more than anything in the world, and the only pet that meets her mother's qualifications is the sloth. After she has Sparky mailed to her, she just wants people to love him as much as she does. Thus she makes several failed attempts at teaching Sparky tricks where he makes the same face I always made in gym class:
Eventually our narrator realizes that it doesn't matter if people find Sparky impressive, because she loves him and that's all that matters.