What do you mean? This entire article talks about how you use bluetooth between the computer and your phone. That is a very unstable and uncertain way to communicate between a phone and a computer. Especially on a stage, where the computer more often than seldom, is a stationary computer without Bluetooth, and even if it has, the range between the stage and the computer is to far for Bluetooth to reach.
The smart and genius function you had, but no longer has, is this (from Prezi Classic).