I think sometime we, as adults, have a tendency to over-complicate things. Leadership and good leader behaviors are not that difficult to understand or articulate. They are tied to right principles: Integrity, compassion, fairness, consideration, kindness....and much more. children, especially at the age of the children in this video, have a strong sense of what is right and what is wrong.
In our grown-up world, sometimes the line between right and wrong seems to get cluttered with a lot of stuff. We sometimes lose the notion that right and wrong are black and white...no wiggle room. Either you do the right things or you do the wrong things. We think we can use our grown-up intelligence to argue about degrees of right and wrong. We "quibble" over nuance and "shades of grey."
Kids, in their purity, remind us that to be good people, we must act in good ways. To be good leaders, we must act with integrity and serve those we lead.