The first time we considered the Composite module, we were focused on the content area and assumed that the other regions on the page were still in use. But what if you didn't place blocks in the regions? You would have only the node. But what if the node could be sliced into regions.
The layouts below represent how the Composite module allows you to divide your node into "regions." Consider the 25/50/25 option highlighted. This strategy, allows you to use your node to define your page layout versus using both the node and the theme's regions and sidebars.