When "Display Saving" is ON, the display brightness is set to a safe brightness level that helps to extend the life of your pen display and reduces the chance of burn-in.
Burn-in can occur with any OLED display if you continuously display the same image. Best practice is to use your OS screen saver if you plan to leave your computer for any length of time.
The Display Saving function is ON by default and Wacom recommends this as a normal operating practice.