These options affect the standalone image viewer.
Automatic slideshow: The viewer will go into slideshow mode whenever it opens with more than one image in the picture list.
Cross-fade transition: Uses a cross-fade effect when transitioning from one image to the next.
Randomize slideshow: This option randomizes the order of pictures in the list when displaying a slideshow.
Slideshow speed: This lets you control the speed in seconds between each image. You can use fractions of a second if desired.