GIRLS: Why would a girl do this? 10 points best answer?

Anyone who says dating site are a joke, are foolish. With all my experience of dating I don't think I've ever felt the way after a first date, then with this girl I just met. The date lasted 4 hours, great convo, good laughs, and best of all.. she's amazing. It would take an imbecile to not be able to read her signs that she liked me. I made it pretty clear as well. After we parted ways I gave her a kiss on the cheek, and said goodnight. As she was walking away, she turned around and gave me this huge gushing smile and said, I'll see you soon. I don't know why but it was adorable. Anyway, here's my question. Why would she upload more pictures and change her profile picture? It's only been 3 days since our date. I talked to her yesterday on the phone and we are suppose to maybe go out again thursday. I understand a girl has got to explore her options, but I'm just curious of what a girls take on this is.