Minimize Keyboard for better full screen view
The graphic on the key looks more to me, to be showing that tapping this key will lower the keypad away from the screen to allow full screen viewing.
:ipad-keyboard:
Its actually annoying to say the least when your using an iPhone and the app developer did not think that while inputing data in the app, you may want to sometimes reduce/minimize the keyboard to take a look at the screen as it was before the data keyboard came up.
Some times the only way around this is to enter your text and hope the keyboard goes away, then tap another input dialogue box to bring the keyboard up again for more data input. Other times it never leaves at all until all data is accepted by the app, sometimes not even then, leaving a small sliver of the actual app in the background appear between menu bars and keyboard.
Jaadu VNC has a nice way to deal with this... Three fingers swipe up the screen to remove menu bars and three fingers swipe down the screen slides the keyboard from view. But its always there when you want or need it again.
UPDATE: I just went into my iPad simulator from the SDK and tested this theory. Yes, that is the purpose of the button. It minimizes the keyboard to allow you to look behind it and to see full screen.
Tapping back onto any input box within the app allows the keyboard to slide back up again ready for data input.
