Sure there’s lots of ways to skin a cat, it depends how your site is set up to flow.
For one, you can enter a Design ID in any custom product’s advanced mystyle settings. That will make that product load with that design. So, one “available image” could be a saved design with just that image already in the design, as a starting point or template for a customer to start with.
Design-ID Products like that can be tagged or categorized easily to build albums / categories of designs whether that be presented as “starter templates” or “popular themes” or otherwise.
Second, we can set up a custom image library inside the app’s backgrounds or foregrounds steps with your images either in addition to ours or completely in replace of ours (you can purchase this add-on in our marketplace).
Hope that applies to your website flow.