Tell me what principal of art this is. What would you draw in this type of principal an why?

Contrast

Explanation:

Contrast is the difference in value, color, texture, etc. This piece has contrast in the value, shown by the differing shades of black to white. You would use this principle to draw pieces that had to show a lot of difference in them, like a portrait, so the viewer would be focused on the person versus the background.