IRL, Customs probably found a discrepancy between what she declared and what she was carrying and they took her for further questioning to see if she was a smuggler, a mule, or just forgetful/careless.
If I brought produce from the US, e.g. an apple or orange, into Name of Country I would receive the same treatment. My apple/orange/etc. would be confiscated and I might receive a fine to "help" my memory for future visits.
True Bouncy ... on one of her later flights into China, the flight attendant handing out customs declaration forms apologized to my daughter because she didn't have any more English-language forms. She offered to help and was pleasantly surprised to learn that my daughter is fluent in spoken and written Mandarin.