Dell S2340T Multi Touch Monitor - Manual (Page 35)

When there is no input source and if the user selects 'USB', a dialogue will pop up and disappear after 4 seconds:
When user selects 'Power Saver' mode, a dialogue will pop up and disappear after 4 seconds:
OSD Warning Messages
When Dynamic Contrast Feature is enabled (in these modes: Game and Movie), the manual brightness adjustment is disabled.