To View Photos:

Select an album to view photos. You can toggle the slideshow using the Play/Pause icon. You may also select a photo to view by clicking its thumbnail or view the previous/next photo using the Minus/Plus icons.

To View Full-size Versions:

Once a photo has loaded, you can click on the photo to view a full-size version. Click "Close" in the lower right of the frame on a full-sized photo to return to the normal view.