Including new art words in the weekly spelling list is a good way to integrate and reinforce new terms. We think of the elements as the basic visual material with which to make art. Is hard to imagine anything visual without the use of one or more of these elements. We think of the principles as ways to work with and arrange the elements. This list is an example list.
Every author seems to have a slightly different list of Principles.
It is about dominance and influence. Most artists put it a bit off center and balance it with some minor themes to maintain our interest. Some artists avoid emphasis on purpose. They want all parts of the work to be equally interesting. Harmony - complex but pleasing visual combinations are harmonious.