Upon opening the Layout tab, you will see overviews of the layout page types. You can filter for those layout overviews you wish to display by selecting them from the Layouts drop down list. A flag icon next to a layout name indicates the default layout instance for any given layout type. The default layout is used if no other layout is assigned based on the page contents.

Note: Non-default layout instances may not be visible to shoppers with the exception of the Article, Product Details, and Collections layouts assigned to selected products, product types or collections. This is also dependent on the shopper’s chosen viewport.

Each time you clone a new layout instance, you have the option to make the newly cloned layout the new default.