One of the reviewers didn't seem to like this effect because it didn't seem as impromptu as what
they have seen on TV. Of course it doesn't. Copperfield, Blaine and Angel make an effort to ensure
that their performances look impromptu, but in reality, they are far from it. The challenge to
anyone performing this effect is to manufacture a situation where it looks as if the choice of
location/window is not important. It won't always be possible, but when it is, your audience will
remember it. For the rest of their lives.