Click one of the numbered buttons to overlay this input on top of the currently displayed Input.

The input will display according to the overlay settings.

Click the button again to remove the overlay with the transition running in reverse.

Overlay Preview

Each overlay can be display in the Preview window by using a right click instead of a left click.
Use a right click again to remove the overlay.

When in preview mode the Picture In Picture Zoom feature described below is activated with a left click instead.

TIP: An Overlay that is being previewed will be sent to the Output automatically when the next transition or cut occurs 

Picture In Picture Zoom

When an overlay is active and set to "Picture In Picture" mode you can right click the numbered button to expand it to fill the screen.

Right click again to reduce the size back to the Picture In Picture settings.