it’s a variable product, with two variations Design option and phone model, there’s two images in design options but when you select option from it it doesn’t load, To load the image you have to choose both variations. is that an issue?
As I know this is how WooCommerce work. But you can easy check it. Go to Appearance > Themes > install and activate official WooCOmmerce theme – Storefront and check the problem. We’ll be able to help you only if image does not change with our theme, but if you see the same situation even with default theme we can do nothing.