Add a lightbox to Shopify lookbook

We have a Shopify site nearing completion. However, our client would like to include a lightbox feature on the lookbook page. We are using this theme [login to view URL] There is no option for it as part of the theme, so we need someone to add one. The lookbook page in the theme uses shortcodes. I've uploaded a screenshot of the documentation which explains a bit about it. We are not using any of the point features of the lookbook, so if it's easier then it is okay for the page to be rebuilt in a different way to allow the use of the lightbox. However, it should still be possible for someone with very little technical knowledge to create a new lookbook and upload images. In your application - please explain how you might go about doing it. Also, I've set the budget at $30 - $250, but am expecting bids at the $30 end - this is not a big job. Thanks!