Custom Fields: Linking a thumbnail to another image

I'm trying to figure a way to link a project, not to another page, but rather to an image that I'll eventually display in a lightbox but for now, it just links to the image in its' own window. That's fine.

I've been playing around with the functions.php file of the Divi theme this came from, since that seems to be where to code is to display projects and the new file can be found attached. Problem is instead of linking to the image, it's linking to the page itself. So I'm wondering if you had any code on how to make it where the image appears properly instead of linking to itself?

Here's the code:

<a href="<?php echo get_post_meta($post->ID, "featuredTwo", true);    ?>">
    <?php if ( 'on' !== $fullwidth ) : ?>
        <span class="et_portfolio_image">
            <?php endif; ?>
                 <?php print_thumbnail( $thumb, $thumbnail["use_timthumb"], $titletext, $width, $height ); ?>
                 <?php if ( 'on' !== $fullwidth ) : ?>
            <span class="et_overlay"></span></span>
    <?php endif; ?>
</a>