Possible Clues:

• Tweezing target
• Long line on a face
• Facial feature of Frida Kahlo
• "Line" over the eyes
• Feature of Bert on 'Sesame Street'
• Prominent feature of Bert on 'Sesame Street'
• Bert has one on 'Sesame Street'
• Sign of lycanthropy, to some
• Mostly not suntanned (apparently) around one's solid hairline?
• Bert has one, but not Ernie