You can minimize the Ribbon to provide more working area in the Reflection window.
To minimize the Ribbon
Click the Quick Access Toolbar menu button.
In the menu list, choose Minimize the Ribbon.
NOTE:You can restore the Ribbon by clicking the Quick Access Toolbar menu button and then choosing Maximize the Ribbon.
If you are using a default 3270 or 5250 keyboard map, you can press CTRL+F1 to permanently minimize or restore the Ribbon.