2. When you're in a place where there is bright light (ex: in a sun light) brightness of your device will automatically adjust . When you try to manually adjust it will don't allow and comes to same position at that time a tost pop will come ''Maximized for best viewing in bright light'' .((it will work when you turned on adaptive brightness))
3. It is telling that it has increased the brightness so that you can view the display clearly . When you're in a place where there is bright light
