If you aren't sure what a retailer exclusive is, it means that the cover is sold exclusively to that retailer. Generally, the name of the shop is on the back and/or front of the cover indicating whose exclusive it is. The inside content is the same as the regular comic offerings, only difference is the cover art.
Here's the art for our latest retailer exclusive cover for Silver Surfer Black #5 and Skan did such a great job. It has a super creepy menacing vibe to it. We are waiting for the final, as this comic will have a "trade dress" meaning it will have the title on it.
You can purchase a copy today here: https://sanctumsanctorumcomics.com/collections/sanctum-sanctorum-comics-oddities-store-exclusives/products/10-16-2019-silver-surfer-black-5-of-5-ssco-skan-variant