If you click your mouse within the slideshow above, the following key commands activated:

N :: Show/hide navigation bar
G :: Open/close gallery
Left Arrow :: Previous image
Right Arrow :: Next image
Up Arrow :: Skip to next image group
Down Arrow :: Skip to previous image group
Space :: Pause/play auto mode

In the lower left of the player is a button to view the galleries. Also, many individual slide images have descriptions if you mouse over the slide.