I am wondering why a still .jpg photo requires rendering?
The reason for this is that PrPro is "creating" Video from your Still Image. For ultimate playback, that will need to be Rendered, which basically creates a "proxy" Video file, to display at ultimate playback quality.
Unless I have done animation with Keyframed Effects on my Still Image, I seldom bother to Render my SlideShows, as I can usually play the Timeline with adequate quality. However, if I have done the animation, then I might Render many times, as I adjust my Keyframes.
Good luck, and hope that helps,
Hunt
