We have different cover and page layouts available on our photobooks. To edit the layout on the cover page, search for the "Edit Cover" button and then tap "Layout". Long tap on an image and dragging it into another page will automatically create a multi-image layout. If you decide to move an image from a multi-image layout to its own page, simply long-tap on the image preferred and the section "Drop here to create a new page" will appear at the bottom.
On Android things work a bit differently and the multi-image page layout is only available when you select more than 80 images.