Now I want to guess about the background story of this experiment. In social psychology, there is a concept of the actor-observer bias that actors tend to attribute their own behavior to environmental factors, whereas observers are likely to attribute the same behavior to actors' own personality. Suppose that I pick a wallet at a crowded street. Then, I take the wallet to the police office. For my standpoint, although I want to take it without going to the police office (get the money), I visit there because I (the actor) am afraid to become a thief and get caught, and think there are so many people watching my behavior (situational factors). On the other hand, people around there or the police officer (the observer) may assume me as decent and honest (personality), regardless of whether or not I believe myself as honest. This asymmetric perception is similar to what this experiment shows.
In the video, many participants believe themselves as whatever such as beautiful, attractive, neutral, ugly, or terrible, but they are amazed when seeing the two sketches of themselves. This is because there are clear differences between the two sketches. What we think of ourselves and what others think of us are different. As Daniel Kahneman points out, we are an animal to believe "what you see is all there is". In reality, it seems two selves are existing: one from my mind, and the other from others'.
*the title of this entry refers to Thinking, Fast and Slow by Daniel Kahneman, but my intent to use the word is different from his use (experiencing and remembering self).