This ad made me laugh pretty hard. It's just so unexpected. Just from the initial look, you see that it's a magician doing a common "feat" performed during a magic show. You assume that even though it seems that there is nothing under the girl, you know there is. Then to put the glassex bottle down at the bottom, you realize that it is a glass piece that is cleaned with that bottle so you can't see it.

It lends the audience to believe that this cleaner gets the glass extremely clean, to the point that it doesn't seem like there is anything there, hence the magician and levitating girl.

This is a great ad. I really enjoyed it.