At it's most transparent, authoritarian style is simply dictating to others what they will do. This has been called the 'drill sergeant style.' But an authoritarian style can be less obvious. Being 'an authority' in a relationship is a way of disguising personal wishes as principles. First comes an insistence on framing matters of preference or opinion as matters of right or wrong. Second comes the insistence that the primary aggressor's preferences and opinions are the right ones. Third comes an insistence that the survivor do "what is right." This is a particularly effective and devastating form of abuse against survivors that are dedicated to doing what is right, such as survivors raised in strong faith traditions.
Also, with an authoritarian primary aggressor, "what is right" usually changes with what he is feeling, so that the survivor is always somewhat confused and intimidated. The survivor is left feeling stupid, unskilled, and reluctant to try new things.