Stop getting duplicate images in post listing

I am currently editing the Granda theme (https://www.saintdo.me/themes/?theme=granda). I have changed the theme quite a lot and I have a product listing that I need to change. The trouble I am having is that when I view a specific range some of the products have the same image but I only want it to show the image once then a list of products that also share the image then if I add a couple of more products that use a new image it just gets the image once then lists the products. I can upload a visual of what I am trying to achieve i that would help clarify!