Some 70D's were a software limited 75KWh. Those cars have available to them a $500 upgrade to unlock the full 75KWh battery capacity (turns the car into 75D). This is different than "uncorking" which changes the firmware of the drive units to provide you with better acceleration profile and unlocks extra power to the motors. Uncorking was available for free to S75D's made after some date (I want to say 2017, but not 100% sure).
Tesla usually unlocks all CPO's, so maybe they took pictures before unlock, or forgot to unlock. It is worth checking though, since there are real 70D's out there which are not upgradable to 75D.