This verse opens with one commanding single word line:
The full stop and solitary stance emphasise the forceful presentation of the gift.
However, this gift also bears a warning that
It will blind you with tears conveying the idea that this relationship may occasionally cause pain and make you cry, just as getting too close to a chopped up onion can bring tears to your eyes.
In this way, the speaker reminds us that the onion, just like a lover, can elicit pain and distress as well as love and passion.
An additional warning in the form of an extended metaphor follows with the words
It will make your reflection a wobbling photo of grief.
This emphasises once more the vulnerability and danger people expose themselves to when they submit wholly and completely to a romantic relationship and reminds us of its destructive potential.