The King Rising was the first original magic effect to be released by the company, paving the way for many inventors to come.
However, it does require a small set-up that must be done under some kind of cover (an obstruction or misdirection).
From the spectator's perspective it is impossible to tell that the performer's foot is out, because it is hidden by the leg closest to the viewers.
Again, the foot remains hidden behind the shoes, which are both physically in the air, creating the impression of genuine levitation.
The key to this illusion is that the spectators assume that there is a foot inside of each shoe, which is a natural assumption.
An obstruction is generally used to hide the performer's action of removing, and replacing the foot in its shoe.