Why would a girl (one of my friend's girlfriend) ask if I think her friend is attractive?

Today, she asked if I thought her friend was attractive. The question caught me off guard a bit, so I just gave a general response, but I don't know if it was just her making a poll, or if there was some meaning behind it!

Why would a girl (one of my friend's girlfriend) ask if I think her friend is attractive?
Post Opinion