Analysis of Delia VI: Fair is my love, and cruel as she's fair

VI
    Fair is my love, and cruel as she's fair:
   Her brow shades frowns although her eyes are sunny,
   Her smiles are lightning though her pride despair,
   And her disdains are gall, her favours honey;
   A modest maid, deck'd with a blush of honour,
   Whose feet do tread green paths of youth and love,
   The wonder of all eyes that look upon her:
   Sacred on earth, design'd a saint above.
   Chastity and beauty, which were deadly foes,
  Live reconciled friends within her brow;
  And had she pity to conjoin with those,
  Then who had heard the plaints I utter now?
  For had she not been fair and thus unkind,
  My muse had slept, and none had known my mind.