The meaning of this passage in Song of Solomon depends on what you think the meaning of the whole book is. If you think that the book is to be taken literally, then the meaning of this is simply that the bride is praising the attributes of her beloved. She is showing that God wants us to be attracted to the person we are married to. However, if you see this book as an allegory for God's love for his people, then you can see the beloved in this passage as Jesus Christ (if looking at it from a Christian, as opposed to a Jewish, perspective). The passage makes us think about such things as Christ's purity and his perfection. It makes us think about how we should love Christ and how he loves his church.