I'm afraid we do not offer any functionality that would allow you to make it so different items show up in your scrolling gallery based on the category the item viewed is listed in or anything of that nature. The scrolling galleries in all your listings will show the same selection of items at any given time.
The scrolling gallery is configured to display 16 of your items at any given time and refreshes automatically every 4 hours. After each refresh, our system will repopulate the scrolling gallery with another 16 listings that are ending around the same time as your next listing that is viewed.
The only way you can control which items show up in the scrolling gallery is by marking specific ones as "hidden" or "featured" from the "Manage Items" section under the "Store" tab. Any items that are made "hidden" will be removed from the scrolling gallery after the next refresh and any made "featured" will always be displayed in the gallery following the next refresh provided no more than 16 are marked as such.
I hope this helps. If you need any further assistance with your account, please feel free to contact our customer support team by mousing over the "Help" tab within your account and selecting the "File Support Case" option.