By default, our Shopify plugin displays the product image using the image attribute.
The main product image in Shopify is stored in the product_image attribute, and the main product variant image is stored in the image attribute.
Unless a product variant image is assigned in the product detail page, the product_image and image attributes of the product will have the same image source URL (product_image URL).
However, if a product variant image is assigned, then the image attribute will hold the variant's image source URL.
You can assign a product variant image on the product detail page via the Shopify admin: