George gets a massage from a man and feels "it" move. Jerry asks him whether it was a "movement" of a "shift," as these are different. This scene can be compared to movements along versus shifts in demand and supply curves.
A seller of hula hoops finds that no one is purchasing his items, so he lowers the price in an attempt to increase demand. His price changes don't make a difference. When a boy finds a stray hula hoop and plays with it in front of his peers, all of the kids suddenly want one, and the hula hoop becomes a desireable product.