If a store is closed and is eligible for shown to the customer's application, it is shown at the end of the stores' list on the homepage with a message "Not Accepting Order" with a grayed-out image of the store to indicate that is is non-operational.
This message can be customized by the Admin.
When a user clicks on a Closed store, they get a grayed-out page and will not be able to place any orders from this store unless the store is set back to Open by the Admin or the Store Owner.