First, I think the shave looks great on you. Second, I don't think you owe it to tell people who haven't met you in real live. But, if you do actually plan a meeting, you probably should say something if they've seen a pic of you with longer hair. Just an, oh, by the way, I've had a bit of a haircut since the pic of me on the site was taken...I mean, you wouldn't want to be looking for a blonde when a brunette is showing up, so it's the same sort of thing here.