I recently used this form to show the full version of a jpg when clicking on its thumbnail:

<a target="_blank" href="/pictures/2013-fame/1.jpg"><img style="margin: 0.5em; float: left" alt="" src="/pictures/2013-fame/thumb-1.jpg" /></a>

I was surprised that a window opened to show the full jpg. Is this the "wrong" way to do it? Should I put putting each jpg on a separate html page? This was done in a hurry because I had 33 jpgs on the page to do.