The wife who is speaking here seems different from others. She has a darker complexion than most of the women around her. In Biblical times, the girls and women who were trying their best to appear as beautiful as possible externally avoided the sun. They wanted to be as white as possible. They do everything they can to avoid getting a suntan. That was the ideal of beauty back then: the whiter the prettier. The wife who is speaking is not beautiful according to the standards of that time as far as her skin colour is concerned. She is so tanned by the sun that her colour is reminiscent of the tents of Kedar and the curtains of Solomon.
5 I am very dark, but lovely, O daughters of Jerusalem, like the tents of Kedar, like the curtains of Solomon.