Getting image variations to work

Hi, I’m having a bit of trouble getting my product image variations to switch the product page photo on my site. I have the swatches showing as product images, but if I click on a different color, it doesn’t change the main product image, unless (it seems) I choose a size option. This won’t really help us much at all. Can you please advise? I am including a link to an example in the private content. Thanks.