VGA to RCA? WTF? A cable alone can't do that. You would need to pass it through some sort of converter. In case you didn't know, you could put your photos in an SD card, insert it into the SD slot in the TV, and use the built in photo player.
Your laptop may have a component/svideo port on the side. Plug in an svideo cable and connect it to your TV, select the appropriate input on your TV menu, and have the laptop output to the TV. Some of the Panasonics have a VGA cable for you to connect your computer to. Ideally, the best way to connect it is with HDMI, or if your laptop only has DVI then by using a DVI to HDMI converter to connect through an HDMI cable.