Why does a girl ask her friends what they think about a new guy she just met?

Please explain to me why if I met a new girl and I’m going out with her later this week, she brings her best friend to talk with me like this friend of her know me a lot, while I never met her before.

Is this a sign for me that the girl I’m interested in is checking me out with her friends before she decide what to do with me?!

Strange to me. I never been checked like that before.