What it communicates: I am uncreative and/or think you have a sweet tooth.
This classic gift sends a relatively neutral message. Yes, she will know you thought of her, but she won't know in what way, or if she was the only lady on your to-do list.
The brand you choose makes a world of difference. Opt for Russell Stover or a Hershey's bar, and she'll assume you picked it up at a 24-hour pharmacy on your way to her apartment. Even if you're not serious about her, if you're seeing her on February 14, the least you can do is give her something that tastes good. No, your penis doesn't count. Spring for an elaborately-wrapped box of chocolate covered strawberries at Godiva, or a custom box of truffles at a boutique like Jacques Torres.