Vanity Mirror Messages

Luz had a hard day at school and all she wants to do it lay down and forget the world. She can't do that, of course, because homework is important. When she sits down at her desk to work she notices something completely abnormal: There is another person inside her mirror. They cannot see her, and she cannot hear them, so why does the person suddenly look so absolutely befuddled while staring straight into Luz's eyes?

OR

Luz sees a person in her mirror, and with nothing but time on her hands, she pulls out a trusty dry-erase pen and investigates.