Select the arrow icon on the image to start the slideshow. Now hit the play button (bottom left) to view or pause the slideshow. To enlarge the viewing area, choose the icon with four outward-pointing arrows (bottom-right); alternatively, to return to reduced-size viewing mode, either hit the escape key or select the icon with four inward-pointing arrows (bottom right).
Note: you must be viewing in enlarged screen mode to turn ON the information (captions) feature: select "Show Info" in the view menu (upper right). Set additional viewing preferences under "Options."