The mark consists of two oval windows of clear glass placed opposite from each other on the front and back surfaces of the bottle. The oval windows are surrounded by frosted, translucent glass on the rest of the surface of the bottle.
The stippling surrounding the clear glass windows in the drawing is for shading purposes only to indicate frosted, translucent glass, not color. The few lines appearing across the clear oval windows are also for shading purposes only to indicate clear glass, not color.