Getting the featured image gallery in php

I’m using the JobRoller theme which is a theme for making a job board. People can register / log in and create a resume for themselves through this theme. The people registering to the website do not have access to the Media images and so can only affect their one featured image. If they edit their resume and put up a new image the old featured image is replaced visually but in the backend I can see that their featured image gallery still has the old image.

I know that grabbing the current featured image can be done in php by writing:
if (has_post_thumbnail()) the_post_thumbnail(‘blog-thumbnail’);

Can I grab the other featured images from that gallery that are not currently being displayed? The goal is to be able to have people without access to the Media images still be able to put a few images of their work on their resume.