A CodePen by Thomas Pauly. Layout Shifter - From Luke Wroblewski's Multi-Device Layout Patterns:

This pattern does the most to adapt across different screen sizes. That is, different layouts are used on large, medium, and small screens. Because this inherently requires more work, it seems to be less popular than the previous two patterns I outlined.

Though I've tried to generalize this pattern into a simple illustration (above) based on the most common implementations I saw, the truth is this is where a lot of innovative design is happening. As a result, there's not one formula that encompasses everything that falls under this pattern.