Depending on the situation, some might call it a squint while others may interpret it as "bedroom eyes." In German, however, a narrowed sideways glance can be referred to as a "Silberblick," or "silver glance." The term originates from the metallurgy field and indicates the moment in the silver-refining process when the last bit of lead has been removed from the surface of the molten alloy and nearly pure silver peaks out from underneath. The "Silberblick" is considered attractive, especially on women, and it was customary in late-Renaissance portrait art to paint eyes so that they weren't focused straight ahead, but down and to the side. That explains, for example, why observers get the feeling Mona Lisa is looking at them.