In the plugin page, on wordpress.org, you wrote the example string using italic to highlight string parameters: [image_archives term_id=? ordered_by=? order=? (...)].
I did a simple copy/paste of the string to test the plugin and nothing was working at first... because of the tags which were copied over!
It's not a big deal, I know, but a newbie could maybe get stuck on this simple problem and remove your plugin.
Let me even say that your plugin just saved my a## with a client, so thank you very much! Geat job! :)