When Ariella saw Toby's look, she gave him a look as if to ask 'What? Did I do something wrong?' She knew that her expression and reaction must have been a bit strong but did they honestly think that she would approve of them meeting at a concert like that? Ariella would have been much happier if Toby had just stepped in and lied about it. Ignorance was bliss in the case of Ari, of course.
She smiled a little when Toby said that Sarah was good photographer. At least there was one more redeeming quality to the goy who he met at a concert of a band she absolutely loathed. "That's lovely. Do you have any photos on you?"