This icon indicates the Picture (or Contrast) control. It affects the brightness that is reproduced for a full white input signal. Once Black Level is set correctly, Picture should be set for comfortable viewing brightness.
This icon indicates the Black Level (or Brightness) control. This control should be adjusted so that black picture content displays as true black on your monitor. Incorrectly adjusting this control is the most common problem of poor quality picture reproduction on computer monitors, video monitors and television sets.
A monitor is properly adjusted when it meets these conditions:
A black input signal should produce true black to maximize the contrast ratio of the display
A white input signal should produce the desired intensity