The Auctiva store window can display your eBay listings, whether they were posted through Auctiva or not.
The store window is set to display 16 items at a time favoring items that are ending nearest the time of the one being viewed, and is refreshed every 2 hours. Once some of your listings end, they’ll be replaced in the store window with new ones at next refresh. We will be increasing the store window capacity to 20 in the near future.
The only way you can control what goes in your store window is by making items hidden. To do this, go to Auctiva -> Store(tab) -> Edit Items. Items that are made hidden will not be shown in your store window the next time it refreshes, which it does about every 2 hours.