Originally Posted by JSWolf
Actually, it's not a screensaver. eink does not need to be screensaved.
As was demonstrated repeatedly on the irex readers you do indeed need to save eink. The safest storage state of eink is 50% grey where the black and white ink capsules are completely mixed in the middle of the oil suspension matrix. This keeps the ink capsules from drifting outside of the EMF produced by the electrophoresis drive grid.
When I got my new Kindle 1 to replace the one that died during the firmware update I was shocked by how much contrast I'd lost over time on my original launch day Kindle 1.
I think the closest publishing term to what the images are would be "illuminations". Interesting images used to fill otherwise dead empty space and provide a sense of warmth and enjoyment.