About the closed preview: it is a simulation, cropped from the exact composed wallpaper shown in the open frame beside it. Your Duo takes the one wallpaper you set and reframes that same artwork when the phone is closed — there is no second file. The exact region shown when closed can be positioned in the phone’s wallpaper editor, so your closed view may crop slightly differently from this preview.
Press and hold the picture below and choose Save Image — it is the full 2670 × 1878 JPG, right here on this page. On a computer, right-click it instead. You can also tap Share / Save Image below and pick Save Image from your phone’s share menu.
