That's easy:
- Create a folder called "drawings" in the root of your KT.
- Create a pic (800x600 and in color**, despite of the KT-BW-Screen) and save it as PNG in the KT folder "drawings" with a name who not contains blanks and/or umlauts.
- After unplugging the KT, you'll find the pic in the library. Set it onto your favourite list.
Now you can easily open it before you leave your kobo alone. The advantage is, that you have always "read" the pic upto 99 percent when opened. So you don't lose the display of the book that you're currently reading.
**Maybe a grayscale pic also works, I haven't tested yet.