Mockup theme shows all the blocks positioned in its respective region on the website, clearly highlighting the place where blocks are placed. It's very useful for sitebuilding when only use mockups as a reference, so you can build the site just defining escencial regions and the final design can be in process at the same time.
Regions are expanded by default but you can collapsed them clicking the title in each region. This theme has very simple styles because its main functionality is showing blocks and its respective regions.
