Shopify Product Variant Image shift

For the Shopify store www.moreismore.dk, we would like to make it possible for the user to change variants selecting an image not only by selecting the variant from a drop down menu. So the dropdown menu shows at any time the variant that is also shown in the main product image. Looking at the website right now illustrates the issue we would like to solve: https://www.moreismore.dk/products/taknemmelighed?variant=41996273647816