When someone shares your Facebook page to earn points it shows a preview of the page but when they post it is text only. I understand Facebook does that but I believe you could allow us to manually insert an image in our settings that we would like to use for every share, like our store logo or ad graphic and then you pass along text in the description to include the URL link that you already have. It won't be a page per se but would work just fine and it would be graphical which gets more attraction and engagement than just text posts.