Two readings. Kept full, 眉目 means a face, or the way a piece of writing is organised. With a neutral second syllable, 眉目 is a different word meaning a lead or a first sign of progress, as in 有眉目了.
usage
The face sense mostly turns up in fixed praise: 眉目清秀 for delicate features, close in feel to 眉清目秀. Applied to a text it means the structure is easy to follow.
