Then if the goal was "show me what you can do", why were students confined within the context of designing a new popsicle?

If a student presented their new idea for an ice cream cone via interpretive dance while wearing a Barney costume, would that also fall under "show me what you can do?"

Right, when the professor choose popsicle assignment, he clearly want everyone to "grasped the difference" and do nothing about popsicle at all. May be everyone of his assignment is always this meta zen like assignment. Kim would have gotten even higher score had he grasped the truth about "what he can do" and just go doing something else instead of wasting time doing presentation, that's really "what he can do".