I'm sure Alex could explain this one to you better than I could. From my understanding of the technique, it's just to set your awareness above and behind your head. The aim is to make you more aware of that location. However, your focus should be on the book. It's kind of like driving. Your FOCUS is down the road, but you can be AWARE of what is going on at the sides of the road. Don't confuse focus with awareness. They're not the same.
~NeverSpeak
