just to add my thoughts, i would call it wallpaper because that's what people know it is. but ideally anyone can download it anyway so it's not really a real perk. i would offer a discount code of some kind like 15% so it's harder to add up. there's already so many landscapes it's going to be hard to compete, so it's hard to know what to say there. i don't know how the ads work there, if they allow photos or not, or if you can choose fonts and colors. but it may just be blending in. if they allow pictures, or if you have a facebook page for them to go to, show them the wares you offer. people are visual and have a short attention span. so a picture of a bright color will attract more attention than anything else.
i would leave out the like my page because to be honest, it sounds needy. i might also call it fine art, and not photography, since your selling the product and not just showing a picture.
when i'm in facebook, i ignore the ads that filter through the ad blocker. it might be easier to filter them through a facebook page, but i find i get very few views there. unless you have a funny quote lifted from somewhere, or recipes, facebook i found isn't that great a place to do really much of anything on.
---Mike Savad