In Narrative of the Life of Frederick Douglass, what do the conflicts between Douglass and Covey reveal about slavery's effects on slaves and masters?

In the Narrative of the Life of Frederick Douglass, Douglass describes the time when he was hired out by his master to work on Mr. Covey's farm.  Mr. Covey works the slaves unmercifully and beats them when their bodies cannot handle the work.  Douglass runs away in an attempt to make a plea to his master.  However, his master sends him back to Mr. Covey.  It is likely that his master does not want to lose money on the deal or to create a bad reputation with Mr. Covey and other plantation owners.  In this situation, we see that slavery has had the effect on masters of viewing people as property and treating them accordingly.

When Douglass returns to Mr. Covey, they end up getting into a brawl because Douglass refuses to be beaten by him.  Douglass overpowers Mr. Covey, but Covey does not admit to having lost the fight.  Douglass resolves that he will be a slave in form but not in fact.  Slavery has had the effect of institutionalizing the racial hierarchy that serves as a power structure in that society--although Covey has lost the fight, he will not admit to it and still upholds his position as master.  Douglass has won the fight and can only resolve to view himself differently from the inside; on the outside, he must continue to perform his duties.