She is sitting among her friends, hiding from view, looking at her smartphone, and unengaged.
Whereas her more outgoing girlfriends are talking to each other, talking to men they just met at the social venue they are in, flirting, laughing, and showing excitement and engagement.
This kind of body language makes a guy look at an outgoing woman as someone they can approach and talk to.
Speed dating is advantageous in that you get to physically see who you are dealing with at the physical venue of the event, such as a restaurant, café, or bar.
Thanks to the rotation setup, which allows you to talk to someone at the event for about 3-8 minutes before moving on to the next person, you get a very good read on what the person physically looks like in real time.