Not a red rose or a satin heart.
I give you an onion.
It is a moon wrapped in brown paper.
It promises light
like the careful undressing of love.
Here.
It will blind you with tears
This suggests that the brown paper-wrapped moon represents light in the dark, the rewards of love.  The light might be the moon itself or the stars around bringing brightness to the night itself.  So, beneath the brown paper is something intended to be positive and tempting to the addressee.
Valentine