Oscar is confident that he believes he has the ability to do anything. In this interviewing, his accomplishments are a bit exaggerated. The employer may find that Oscar is too confident about himself, which is not good for a job application.
Ashley is introverted, and she is always worried about herself. Before the interviewing began, she was thinking about what she should be answering. During the interview, her brain does not function in the way she wishes. She is not able to answer those questions properly.
Robert is calm, and he also understands the main idea of this job interview, the employer requires him to present himself. That's what he does in this interview.
At last, the employer finds out Robert is the one who performs the best in this job interview, he has appropriate body language while presenting himself. So he gets his new job.