Product images show full size of Featured Image on main store page

You can see our main store page here: http://www.trailsherpa.com/market We are pulling products from the subscriber sites in our MU environment. But the image size is the full size of the uploaded Featured Image. The images appear appropriately on the site as per the site settings but on the network site we can't seem to find a way to create a uniform size (like the network thumbnail size) for all product images.

Any way to do that?