I was shocked to see that it's not possible to show the images in sequence!
Another idea to solve my problem (currently I'm using a folder with 60 images only): make the random image selector more random. It would be great if you store the information which images have been already shown/used. So I can be sure that every image will be shown once until the loop starts again from beginning.
Sorry, my sentences sound horrible today. Maybe you understood my issue anyway.