I have the PTID 7002 but im sure its the same solution, this is from Power Acoustik:

You need to have the remote in hand. Insert a memory stick or SD card that has the images you want to use. When the image is displayed, press the pause button on the remote. Then touch the screen to bring up a set of icons on the bottom. If you do not see an icon with a hand, press the arrows that are in a circle until you do. Once you see the hand, press it one time. It will save the image onto the internal memory. You will find the image in the screen tab in settings, under all the stock images.