I called Baylor today to see if they ever received the optional photo that I sent by mail a month ago, and they did not. However, the woman I spoke to said not to bother wasting more postage, since they don't even see it when they review your file, and you may as well just bring it if you get an interview. She said that they're really on top of opening their mail (i.e., there's no pile of backlog). So, for those of you that haven't completed Baylor's online secondary yet, don't even bother sending in the optional by mail photo. She said that they have actually only received ONE photo this season so far, and that it has no impact on applications whatsoever.
Funny, but she mentioned that she remembered creating my application file, and hopes I get an interview. It means absolutely nothing, but still nice of her to say. Very nice admin staff there.
Interview invites will start to go out by email in about a month.