It is possible to display more than one image of a product on the product page. You can only upload one image on the artwork tab of the product. However, you can add more images in the product description page.
Path: Admin > Sites > [site name] > Product > [product name] > Description tab
Once you go to the description tab, you will see the long description area. Here you can add more images via the image manager. See the screenshot below for information about accessing the image manager.