Liam is feeling all small and shlumpy in his loneliness as all the other kids have someone else to play with, whereas he is all by himself. Mr. Anthony shows him how to do the super hero stretch to make him feel less small and shlumpy, but it doesn't change the fact that he is all alone with no one to play with. So Mr. Anthony tells him about the time Napkin Man visited Super Fun Land and managed to have fun while his super hero friends were busy having fun with each other playing games in which he couldn't participate at that time.
—Huggo