Use the preview window to view how a label style will appear in the drawing. When you make modifications to the label style, the preview window updates.
The preview window is located on the General, Layout, and Dragged State tabs of the Label Style Composer. You can select a different preview by selecting it in the Preview list.
To change the view in the Preview window, you can use AutoCAD commands on the context menu, such as and Zoom.
Previews are actually stored as DWG files in the \Data\Preview folder. If you would like to add your own preview drawings that contain specific label styles, you can place the drawings in the Preview folder.