As an artist - especially a portrait artist - you have to become very familiar with the human skull. It is the foundation of the face. If you are ever going to accurately capture someone& likeness, you need to understand what lies beneath their skin.
The skulls at the bottom look very sinister, it looks like the skulls are laughing. Another idea that I could do in the future would be to have the 'Trivialised to Death' skull laughing as the screens of the skull are changing.