The metaphors are mixed in this verse as she describes being intimate with her husband with the use of scents and tastes.
The first metaphor is of a garden of spices and herbs. All adult Israelite men wore beards and so the garden she describes is his beard, and these beards must have been perfumed. Thus, a garden of spices is an apt image.1
The second metaphor is of lilies dripping with myrrh which describes his lips. In Song of Solomon 1:2 and Song of Solomon 4:10–11, these senses of scent and taste were associated with kissing, and the same association seems to be made here.
This is not so much a description of his face, but rather an expressed longing to be close enough to smell his scent and for her lips to be able to graze among the lilies of his lips.2
13 Ses joues sont comme un parterre d'aromates, Une couche de plantes odorantes; Ses lèvres sont des lis, D'où découle la myrrhe.