Dale kept thinking about his conversation with Sarah, he really doesn't want her to leave, but he can't do anything for now to stop her.

And the time came to go to his first exam.

As he leaves, he sees Riley outside in the yard, playing guitar. Her eyes are closed so she doesn't see him (or pretends not to).

She probably thinks Sarah is still in the igloo, she didn't realize that she went in the house a while ago.

Whatever, Dale doesn't want to talk to her, nor does he have time to snap her out of her mistake, he has to get to his exam, so he continues to his car and let her go on with her serenade.

Riley stays there, playing with great feeling. She may seem harmless to anyone who doesn't know her well.