> The card itself may have contained other security features such as a holosticker or a serial number in human readable form.
It doesn't. It has the word adult, the opal logo and the new government logo on it. On the back is the remember to tap off message, phone numbers, website, the card number and 4 digit security code. Certainly nothing a human can use to spot a forgery.
I would be utterly amazed if security wasn't handled by encrypting the data it holds.