Sarah was standing on the second floor in the mall and witnessed the whole episode. Standing there and looking at them from a distance, she remembered that when she had been Charles's secretary, they had gone out on similar business trips. She had often secretly bought gifts for her sister when they were in the mall. But when they came back to the office and Charles saw it, he would scold her for doing personal business while working. His attitude had been entirely different from today with Emma.
Once again, Sarah came to the conclusion that Charles always indulged Emma and believed in Emma, punishing Sarah for the tiniest mistake, even if it were made by Emma, he'd think that it was her fault. Why was he making this difference? He was married to her after all.