Welcome to the Shopify Community!
This is Jay from Oakleaf Infoway.
I am Interested to help you and get out it of you from your current issue.
I got your point and as I am sure you want to set-up your product image galleries like the below example.
I would glad to know you that it can be done by some coding but still need to check as you are using debut theme.
Would you be interested to discuss this further in detail?
Please add me over skype for instant communication.
Email ID& Skype ID: firstname.lastname@example.org