Adelaide ecommerce theme - Adding content to your cart page
From Spiffy Stores Knowledge Base
To add content to your cart page, simply create a page called "Shopping Cart" in the "Pages & Blogs" section of your store's admin, and add content to that page. This content will appear right below the title in the cart popup window.
Please bear in mind that adding images to this will undoubtedly make your cart unusable on mobile devices. The function is intended so that you can add a short note to the page, not an essay.