Being a media theory major, I have been asked to critically analyze many forms of media. Hook presents an interesting perspective on media in regards to representation of norms and expectations. She wants viewers to realize that the racist and homophobic beliefs have been instilled in them by media's machine of portraying those on screen.
Hooks uses a lot of two dollar words in an attempt to stress her point of assessing media's representation of culture to the viewer. She uses one term frequently, "White Supremacist Capitalist Patriarchy." At first, I thought this was a cleverly coined term, but by the end of the documentary I thought she was a crazed feminist. All throughout the documentary, with the exception of the OJ portion, I just really wanted her to not talk anymore.
It was as if someone had pissed her off and she was on the attack. This perception carried throughout the entire documentary.
To answer your question, she talks about cultural expectations in media and how they form our perceptions and that we must train our brains to analyze the moment they fit into "that" mold.
Finally, In regards to Hooks and her comment, that we must be "enlightened witnesses when we watch represenations," I believe she wants the public to take the media for what it is worth. To see an actor portray a black character as just that, a character on screen. We must begin to assess that our media expectations do not follow through into reality.