If I get the clip right, he is forcing banter with the 'execute: tdu' command, whatever that does.
The banter seen in the video plays randomly throughout the game while playing, whether it be while opening chests, running around or slaying enemies. It was just done here by a command prompt so people can hear a lot of the potential dialogue and banter while playing the game. (All of the banter is done in real-time during a playthrough of any level)
