I'm looking to wanting to add a "thumbshots" of the featured site to the left of the title and description as well. Just the text part makes it look too plain. Any help how to perform this would be grateful.

The featured links, reviews etc came about before thumbshots provided their free service, so getting images up for them is a bit old school.

You can create and upload your own pictures, so for example, if the site ID 2 is a featured site, you would create and upload a JPG image for it, making is brows-able at
/images/featured/2.jpg of your installation

Admittedly, it's a bit clunky. The files involved are
/includes/random.php and /include/review_inc.php

Code in /include/review_inc.php looks for the existence of a corresponding JPG file, and if so uses it, but keep in mind a featured site must have at least one review.