Originally Posted by kacir
No. It is not unnecessary. It is an important feature.
Due to nature of e-ink screen, and due to nature of usual reading activity - turn page, read for XY seconds, turn page again - the device is idle most of the time.
The device loads and displays the page and switches itself off. This is why ordinary small "cell-phone" battery inside can last for weeks.
So, it is important for us to know when the device is working. This is indicated by that LED.
The device doesn't turn itself off after every page load it's simply in the nature of e-ink displays that they don't require constant power to maintain the image once drawn.
When a user presses a button he knows power was used by the change in the display, same goes for using the g-sensor to change the page orientation.
That LED absolutely does not indicate that the device is working, it doesn't stay on constantly while the device is active; If a user doesn't have its device set to conserve power by turning itself off after x minutes of inactivity (found in the clock settings on my 602), the device will continue to draw power until it runs out.
This LED will at no time remind you to turn the device off, it only stays on for a few seconds after you took an action.
Give it some thought ... do you really need to see the led turns on when you can see on the actual display if the action you made resulted in a reaction?
Do you really need a constant reminder every time you turn a page ... that the drawing of a new page takes power?
Is it that constant reminder that power was used so important to you ... that you need to used more power by turning on a LED ?!