This page uses the special page template « Lookbook / Index ». The page shows posts grouped by categories: if you do not specify the categories to include, it will show posts from all the categories. The values you can specify for this template are: « Categories to Include », « Posts Per Category », « Posts In Each Row » (2, 3, or 4), and whether you want to show a sidebar on this page or not. Select the categories and drag/drop/sort them in the order you wish to display them!