The python program was simply the server the attacker sets up. It could be run on any machine connected to the Internet and then accessed by the shell program from the user's device. The emulator and server were run on the same machine to make it easier to record the screencast, but the method works just the same on a real device and a remote server. There is nothing really difficult about how it is done, it is explained in the linked presentation, it is just a nice demo of it.