Expand mode is used to expand an object and show its parts in more detail.
Steps to expand an object:
Click on a slide and click on the Mode tab in the Ribbon
Find the object you want to expand in the Scene Hierarchy Tab
Drag the object to the Expand Root property in the Mode Ribbon. You can also drag it to the Expand Root property in the slide's Properties Tab, it is the same reference.
In the Mode Ribbon drag the slider to the desired amount of expansion.
You can specify which axis to expand the model on using the axis check boxes
You can change the expand algorithm from the drop-down menu to change how the model parts react to each other.
Experiment to find the one that works best for your model.