If it draws low amounts of power it's a low power mode, plain and simple. If this is done by turning off pixels is irrelevant. And btw neither black AMOLED pixels are completely off. Proof http://talk.maemo.org/showpost.php?p...8&postcount=43

Edit: probably the controlled light emission isn't what makes it low power. The lcd backlight draws power in the single mA digits when in lowest brightness. The screen of the N900 even with backlight off draws 80mA