You're further ahead in this week's reading than I am, Tom, but I'll give it a try. IMO Mr. Elliot may have looked at Anne longer than usual without turning it into an embarrassing stare (remember that in P&P Darcy is constantly looking at Elizabeth), I don't rule out a slight double take ;-), and also remember that in those days people were much more attuned to subtleties of behaviour because obvious behaviour just wasn't an option! Another Pemberlean once mentioned that when you're looking at something that gives you pleasure, your pupils will automatically dilate. I don't know if the party passed close enough to Mr. Elliot to notice this about his eyes, but it might have been one of the signs of his admiration.