The DPAN (device number) is the encrypted card number and for security reasons only the last 4 numbers are disclosed. The last 4 numbers are shown to facilitate returns and refunds. The number is unique to each device the card is added to.
When an item is returned any monies due are returned to the original payment method. This is a requirement of the payment method (Visa, MasterCard etc).
The DPAN number will be different on two different devices, even if the payment method (credit card) is the exact same card with the same number. The device is irrelevant.