When the upper-face or the area around the eyes are shaded or appear as if they are shadowed. Can show disgust, anger, shock. It is used for comedic purposes, and can be either used subtly, when a character is upset and trying to hide it but their expression betrays them or with exaggeration for comedic effect.

This doesn't refer to cases where a character is in shade or her face is shaded because of a hat/umbrella/other object.

See also

• faceless
• turn pale
• hair over eyes

Read the full article.