Lakoff also wrote a book based on this lecture, titled "Don't Think of an Elephant!" where he tells us that

Frames are mental structures that shape the way we see the world. As a result, they shape the goals we seek, the plans we make, the way we act, and what counts as a good or bad outcome of our actions. In politics our frames shape our social policies and the institutions we form to carry out policies.

Every word we have is defined relative to a conceptual frame, even trying to negate the frame activates the frame. So, if I tell you "Don't think of an elephant" you will immediately think of an elephant!