Click on a picture to see thumbnails of pictures associated with the topic. Thumbnails and pictures are shown on a New Page - so that you can just close the window for that page without needing to hit 'Back' and wait for the screen to re-draw.
Click on a Thumbnail on the new page to see the enlarged picture on a Second new page, navigate among the enlarged pictures with the '<Previous|Next>' arrows at the top of the page.
Depending on your browser's settings, it may complain that the New windows are 'Pop-Ups', and try to block them. Internet Explorer settings (which you may want to change) will allow you to show subsequent 'pop-ups' from this site without blocking or warning.
Remember that with Internet Explorer the 'F11' key on your keyboard will turn Full Screen Mode on (and off) for an even better view of the pictures.