Going by the YouTube account name phildman14, the developer created a custom Siri Program plugin in his iPhone that can control the things in his room such as the lights, fans and curtains.
He was able to do this thanks to the Siri Proxy created by Pete Lamonica. The program helps developers create different plugins that interpret voice commands and perform programmable actions.
Custom plugins have helped other developers control their car or the thermostat or play the movies and TV shows with Plex via voice commands. Google Voice or Control Mac apps can also be used with Siri.