Drupal Theme Layer Illustraiton

In a few short weeks I will be presenting an introductory theming lesson at DrupalCamp Atlanta. One of the main goals of my session is to have the audience come away from my presentation with a very solid understanding of exactly how the different pieces of a theme and the rest of Drupal work together to produce an HTML page. To that end, I've begun working on a diagram to illustrate the different pieces of a theme and how they work together.

View the (very large) first draft

I'm not an expert of infographics. If anyone has any input, criticism, corrects, etc., please let me know!