Variant image overrides the default selection.
I've got around this by adding another (nonexistent variant) "choose you color" (or whatever your variants are) and attach mail image to this variant. The problem as you might guess is that in some cases (like my last product) that picture shows one of the variants, so the customer doesn't change the selection and buys "choose you color" variant.
Now I have a sale that's not recognized by suppliers system and can't make the order.
Can we please have a simple solution for this, without having to temper liquid code? I'm not a coder, but it doesn't look like a complicated piece of code. We already have the option to choose the default image, only thing to be added is to make it precede (overwrite) the variant image.
Then again, I'm not a coder so this might be more complicated then a layman can notice.
Thanks, Zahrastore! Your long answer actually had the clue to solving this long-running problem!
Here's what I found out - based on your tip: While you can set the default image for your product to be displayed in collections and in the Admin backend, the default image for a product (on the product page) is driven by the order (position #) of the variant in the Variants Section, and not by the order of the images in the Media Section of the Product Page in the Admin Panel. Shopify displays the image associated with Variant #1, regardless of what image is set to default in the Media Section.
Therefore, to set the default image on your product page, click on the "More Options" drop-down in the header of your Variants Section, and select "Reorder Variants". A pop-up opens, but it will not show you images to pick. Rather, it will show you the combination of options that drive your variants. What you need to do is reorder preferably only 1 option, advisably your COLOR option, by clicking on a color and rearranging it. To be safe, make only 1 change at a time, hit Save, and see if the right variant has moved up to position #1 in your variants.
Once you do that, the default product image will be associated with Variant #1.
PS - By Variant #1 or position #1, I am referring to the first variant at the top of the list of variants, in the Variant Section on your Product Page.
I kind of figured this out, although is still not working, however, if the featured image is not one of the variants it does not solve the problem.
I am having the same issue here.