Currently to set a product image for a variation you have to edit the variation and upload a product image in the product gallery section. This is painful if you have 3 colors and 6 sizes for a total of 18 products to have to upload the same image 6x (one for each size). There should be some sort of bulk edit feature to set the product image for multiple variations at a time.
Clicking on the variation thumbnail in the Variations meta box should probably just launch the media modal to select a variation thumbnail. That would seem like a fairly elegant solution I think?
Currently to set a product image for a variation you have to edit the variation and upload a product image in the product gallery section. This is painful if you have 3 colors and 6 sizes for a total of 18 products to have to upload the same image 6x (one for each size). There should be some sort of bulk edit feature to set the product image for multiple variations at a time.