To view larger pictures and see captions, click on the picture. This will open Picasa. To view the slideshow with larger pictures, click on "slideshow" once you have opened the Picasa site by clicking on the picture. (You can find "slideshow" on the right hand side and about halfway down on the Picasa page.)
If your picture does not immediately enlarge, your server may be blocking the "pop-up". Change your settings by disabling your Pop-up blocker when using this site.