How do you actually download a picture when you click on it? Is there some kind of a javascript code to do just that? Here is how i show the image with pure HTML.
I trick this out a bit - I zip the picture and put it somewhere. Then, instead of using a fancy script or server-side stuff, I make the picture's link the location of the .zip file. The user get's warned/asked if they want to download this zip and voila...
But this is usually in an area where the user is someone who would want the image...