Image Popup Template

I’m trying to display images as a popup.
I’m using the Shadowbox plugin, and I’d like to display an HTML page that includes a photo and a description, that has been styled with CSS.

The issue I’m having is that I’d like to create a template, where my client can create a PAGE with the image description as the page content, and perhaps add an image shortcode corresponding to the image to be displayed.

I’m trying to figure out how to style the seperate template, so that if they were to write, for example:

[image-shortcode-here]
“Ipsum, etc etc”

That the template will place the image/text in the corresponding places.
Is this a JQuery solution?

Thanks.