Hi Shawn – sorry to take so long to reply.
The way the plug-in works is by hooking into the post-rendering as a filter. This means it only parses the HTML of the blog post (single or multiple) rather than the overall page being rendered.
If you were concerned about the images in your template then you can adopt the same technique of moving the visible picture into the background (via CSS if you wish to copy the plug-in) and placing an IMG on the top which is a transparent GIF.
The motivation for the plug-in was for a photographer friend of mine. Unless you have a very dynamic template configuration I don’t think you would really want to try and process the output of the entire page – too much hard work for the server!
