When listing a variation item to eBay, the gallery of the listing is only going to include the photos tied to the parent item. One thing you might see are totally different photos that are attached to you variation items in the description. The reason for this is because the Use Variation Images in Default toggle is on. If this is something you don't want to see on your listing, you need to make sure that you attach all the same exact photos to the variation items as well.
Similarly, you might see that your description is showing duplicates of the same image. This can be yielded if you have different image URLs tied to the variation items. It will give the impression that it's duplicating the same photo, but it's actually just different URLs meaning that they are different photos. One way to verify this is to go into the media galleries of your variation items and open the duplicated photo in the browser for each item and see which link is the one that differs from the other.
Or if you don't want to do this, you can do an export of you items and take the image URLs of one item and make sure they match all across the other variation items and perform a bulk upload to import your images.