Quick instructions for getting the desktop pictures on Macs, FYI:

 1. Download the themepack file.
   * The filename is "FINAL FANTASY XIV-A Realm Reborn.themepack".
 2. Download a program called The Unarchiver. More info on its product site.
 3. Drag the themepack file onto The Unarchiver application icon.
   * This creates a folder called "FINAL FANTASY XIV-A Realm Reborn".
 4. The desktop images are inside that folder, in the "DesktopBackground" folder.
   * The images are 1920x1200 in size (16:10 aspect ratio).