Two lines are all it takes here, and they hold a quiet, slightly teasing kind of love. The speaker imagines the person they adore listening in on the way they describe them to others. The claim is that if this person could hear it, they would fall in love with themselves, just as the speaker has.
What stands out is the word "too." It tells us the speaker is already smitten, and that the person being praised may not see their own worth. The speaker isn't only declaring love but offering a kind of gift: a mirror made of words. There's a gentle sadness in that, since the person apparently can't hear any of it, and the admiration goes unsaid.
The mood is tender and warm, with a little shyness. The lowercase "i" and the plain, conversational wording make it feel like a private thought, something confided rather than announced. It leaves you with the sense that love can be seen most clearly in how we speak about someone when they're not there.