Enlarge any of the photos by clicking on it.  To contract it, just click on the enlarged photo. When a photo is enlarged and the pointer is over it, depending on which browser you’re using, a panel may be superimposed on it which looks like this: Click these icons respectively for: previous photo,  slideshow start/stop (5 sec interval),  next photo,  max extent,  exit. If you have a keyboard, the following keys do the same: left arrow,  spacebar,  right arrow,  n/a,  escape