@iSuite I’ve been fighting with item images since day one of SCA. The documentation has some information about that, but I’ve always found it to be somewhat confusing at best. I’ve had good luck with simply alphabetizing it, but if your images above aren’t working, that might not work for you. The documentation (under Commerce > Store Front > Web Store Items > Item Images > Setting a Default Image) says you can add “.default” to the end of an image and that will make it the default, but I’ve found that to be tricky at best.
Really, the best advice I can give you is just to keep experimenting with it. If you use the Network tab in dev tools to open the request to the items API for the PDP page that you’re viewing. you can view the ordering that happens in the JSON request. I find that to be a little easier that trying to figure out the order by the thumbnails.