This is how you will see Rock Perspectives Photo Screensaver in your Screen Saver Setting which will allow you to set a specific time to wait for the screensaver to start 

The Image Saver Setting window shows Options about the image size, transition settings and image sequence options, as well as conditions according to which the screensaver should stop 

Here you can see a sample image that will be displayed while Rock Perspectives Photo Screensaver is running 

And here there is another sample image that will be displayed while Rock Perspectives Photo Screensaver is running