Invisibility cloak illusion
People-watching is an age-old pastime. People notice and observe the people around them all the time—on trains, at cafés, waiting in line, at cocktail parties and office meetings, and beyond. Pretty much anywhere there are other people, we spend a good deal of time watching them, wondering who they are, and assessing what they are like. But despite all the watching people do of others, people rarely feel as if they, themselves, are being observed as they go about their daily lives. People feel relatively invisible.