During the slide show, you can access a toolbar on the upper left screen corner. Move the mouse cursor to the top left of the screen to access it.
With this tool bar, you can drive the progress of the slide show. You can pause or play the slide show, go back to the preview image, go to the next image, and stop the slide show.
In the lower left screen corner you can see the current image file name, the current image ID, and the total number of images included in the slide show.