It would be really nice feature to be able to pick a page from a pdf / gif / jpg / etc.
And that have that show up on the e-ink screen when the device is powered off.

Obviously this could be used in the individualistic/artistic sense (ie. like a desktop wallpaper), and then you could leave the device off/sitting around with the e-ink side out/up.

However, it could come in handy if you wanted to have the device off but still have a piece of information up in a more permanent manner (eg. map, other handy things I have not thought of).

That is just my 2 cents. (maybe you can already do this and I just missed that menu)