This option is only available for blank designs/fully editable templates.
Using this panel type will enable you to:
Select a panel
After selecting a panel, hold down the Ctrl key and then click another panel(s). This can also be done if you click and drag around more than one panel.
Move a panel
After selecting a panel, click and drag into position.
Resize a panel
After selecting a panel use the blue pointers to click and drag to adjust the size.