Hi Sunster,
You can certainly upload pictures to use as the background display. They have to be .bmp (as opposed to .jpg) and cannot be any larger than 640 x 480 pixels. If you put a smaller pic in the TY will tile the picture to fill the screen.
Not sure how useful this is though as there is quite a lot of info on the screen so you will not see much picture. Having said that I think you can customise the screen to get rid of info you do not require.
You can also upload little icon size pics to use as song/style identifyers.
Hope this helps
Tony