From that sub-menu set the enlarge playlist option to be un-checked & also ensure the playlist tab option is checked. Then select the playlist tab (left-side of the window, top of the buttons in the embedded area) & then depending on the state of the skin it might just show the artwork to the right of it you may need to find the resizer to the right of the playlist (but not the outer window) & drag it to the left so the artwork area will then be expanded. If the media library or some of the other embedded windows get set to be shown then it'll undo most of that or so it seems to be from a quick play around to try to figure out how to get to the shown preview image.