The Kindle hardware can make a great picture frame. It is grayscale, yes, but still looks good and keeping the image on that screen consumes almost no power at all.
The Kindle does not offer out-of-the-box picture frame functionality, but there are some interesting ways to do it without requiring jailbreak.
The feature "display cover" changes the lock screen image to the cover of the book open when the screen was locked. By making books with custom covers anything can be used as a lock screen image.
Settings -> Device Options
I made this tool to help with the process.
EPUB is a simple format, this tool makes the
.epub by zipping some files with
jszip on the client. I got the required files by dissecting the output of
epub-gen and modifying them on the fly.
.epubs are great but they are not supported by the Kindle. To send them I use
Calibre but any other way to convert and send
.epub should work.
Now open the book and lock the screen, that's it! Enjoy.
Some kindles have the hidden option to disable the lock screen, making possible to open an image and leave it on the screen without time limit.
To disable the lock screen go to the kindle home and type
~ds exactly and
enter. That's it. This not only allows anything on the screen to stay
without time limit but completely disables the lock screen. To restore hold
power for 20 seconds.
Then transfer an image directly, open it and double-tap it to expand it.
.epub to Kindle transform required.