You select a page from the navigation menu to the left to view the various galleries.  It is recommended that you view the galleries with a screen resolution of at least 800 x 600.  Each gallery holds five to seven pages of photos, displayed in a slideshow format.  Click on the left and right arrows to browse the gallery, and click on a thumbnail image to see a larger version of the image below it.

Although the images are all larger than 640 x 480, they will be displayed in that size on the gallery pages.  If you save the images and view them later, they may be viewed at full size.