Hi,
The issue is that you've uploaded webp images as the images of your products and shadowbox, the library used for the popup system there, doesn't support webp images.
By default, this is not possible as webp images can't be uploaded in products. In fact, we don't recommend you do. You can just upload the normal jpg image of your product, and if you have the "Generate WebP images" setting activated in your HikaShop configuration, it will generate the WebP images for you. And in that case, it will provide the JPG image to shadowbox so that it can work properly. This also has the benefit of backward compatibility with old browsers not supporting the WebP image format.