different product image appearing on iphone vs. ipad

Setting up first product(s); created a white domino and a black domino product. When I edit/add to cart on the ipad it is black and when I go to my iPhone it is white. When I re-edit on either iPhone or iPad, the cart version appears. Thought it was because there was a white version used as a bounding box - changed that to black and cleared all browser cache. > happens in both safari and chrome on iphone > page engraveddomino.com/product/custom-black-with-spinners/ If I knew where the white domino image was coming from on the iPhone, that would help me - brand new to this tool. Thanks in advance!