I think the letter in anonymous, and told him that there is someone out there who loves him and to come meet that someone. And even though he doesn't believe that it is either true nor deserved, he came to the meeting point, having nothing to lose. And no one showed. And he is thinking, "There, you stupid git. I told you this was a cruel prank. Who could possibly love you?" And in about thirty seconds, Harry is going to apparate, and fall on his ass at Snape's feet, with a broken nose or something, because of course something happened to delay him, and Snape, after healing him, will jump to the conclusion that Harry was mocking him with the letter. But Harry will grab him before he leaves in a huff, and offer himself to Legilimency, revealing all the love in the depth of his heart to a disbelieving Snape, who of course had hoped all along it was Harry who'd send the letter. And they will kiss as they whisper endearments and promises, and they will live happily ever after.
At least, that's what I'm thinking...*Nods*
Inspiring work, I would say! PS: How big is it? (The sculpture, not Severus's cock nose, silly!)