Google Image Search results and Lightbox design pattern

Hey everyone, I have a question that relates to SEO and UI design. A common pattern a large array of images in a cohesive form in a page is to use a Lightbox component. The basic markup of a Lightbox image is as follows.

<a href="path/to/full-res-image.jpg">
   <img src="path/to/thumbnail-image.jpg">
</a>

A link to the full-res image wraps a thumbnail version of the image. When the thumbnail is clicked, the link is triggered and the full version is overlaid in a modal.

Now, my questions pertains SEO, primarily Image search results. If the <img> tag that is on the markup in the document is linking to the thumbnail, will search engines just display the thumbnails on the search results? or is there a way to make the search engines follow the link and index the full version of the image?

Thanks!