As you'd expect, the Workspace retail shopping cart starts with the customer choosing an image, maybe a landscape in Print Shop or a family photo in a Client Gallery.
Either way, once they've chosen the image Workspace asks them to choose a product to put it in — products that you as the photographer have decided to sell.
Workspace's wholesale shopping cart, on the other hand, starts by asking you to choose the product first, and only then, the image(s) to put in it.
Why the difference? Because chances are you've already uploaded the images into a gallery.
You will, however, have the option of uploading more images on the fly.