It is an optional ECU program upgrade that boosts the HP slightly and increases torque by a fair amount. It should be noted in the options list that came with your car unless it was a mistake by the factory. Does you car have the Polestar Logo badge next to the XC40 logo on the tailgate? I have heard of someone that purchased a car that had the upgrade installed that was not charged for it and it was removed from the car when the car had a software update done when it was serviced.
Score! In my humble opinion, I feel the ratio of $ to performance isn't worth it... for those that want to cheat, you can buy the Polestar badges on Amazon for about $25 (I bought one haha). I did it just for the looks.