As a new user, you start creating your online inventory by adding your items, one by one. It is a long process and you won’t finish it in a single “visit” in the Byebye app. So, until all your stuff is updated you can leave the inventory Open, as other users can see that it is not in a stable state yet.
After you finish adding your last item, turn the switcher in the Closed position. The state of inventory should stay Closed if you don’t have other items to add at a moment.
The other users will see your inventory status wherever your details are available.
Useful tip: people are more interested in the closed inventories, as they reflect better the context of a user.