Maybe it was for a reaction, maybe not. Don't take it as anything, but what MrBond said, just her dropping off a book. Even if she did look lovely doing it.
About your previous post, there is most certainly a connection between you two, I could honestly feel it when you described how she was looking at you, and you had to look away. But, like everything else, take it with a grain of salt.
Maybe like you hope, some of the wise old heads will come to post. I asked God to make me wise, but He gave me red hair instead, with an Irish temper. Oh well.
Just wait, if she wants something more, she will eventually let you know.