Sing-Yi receives a $100 debit card every month from her employer, the Porter Group. The debit card is limited so that it only can be used to purchase fare cards and passes on the Metro Transit line that operates trains and subways in town. Sing-Yi throws away the card when it expires at the end of the month, and she is not required to provide any records to Porter about how the card was used. The card logo says “American Airlines Visa,” and Sing-Yi picks her own password for the card. Does the card represent $100 monthly gross income to Sing-Yi? Explain.