I just purchased a GPX

The type of pictures that you can store in this player are JPEG (JPG) pictures.

You can read the step by step instructions on the user manual page 5
http://www.gpx.com/owners_manuals/ML6X8B-IB.pdf


After you have loaded pictures into the unit heres how to view:
Viewing Photos on the Unit
1. Press the Power Button to turn the unit on.
2. Press the Volume Button to navigate the main menu and highlight the Picture
option.
3. Press the Play/Pause Button select the Picture option.
4. Press the Mode Button to access the Local Folder and Play Set. Select Manual
Play or Auto Play
5. Press the Play/Pause Button to begin playing photos on the unit.
6. Press the Skip/Search Buttons to skip from one photo to the next or previous
photo.