The essay or report needs to have an hypothesis or question to pursue - in any area that interests you enough to be able to do some significant research. The key element is integrating a close analysis of one of the exercises into the larger topic, whether that topic be history, philosophy, science, performance, education, sports, or psychology. The close analysis may relate directly to the work you have done on the video exercise, but should not be a simple repetition of that work.
The reason that you are asked to use an exercise we learn in class is that the main learning experience of the course is to understand some of the principles involved in a daoist movement system. These systems have existed since before recorded time, ie since before 3000 BCE. They are places where people have tried out their relationship to things in the world, and to other people. From these relationships they have acquired an understanding of the energy in their own bodies and how it complements the energy in their environment. This is the main meaning of the 3 daoist virtues that I talked about in class: kindness, respect, and an awareness of balanced ecology (benevolence, humility, frugality in the old vocabulary).
The principles are the ways that we bring the virtues into reality in everything that we do.