Sweden has long and cold winters and thus, also a very long tradition of pre-heating the motor and the interior of the car. The Shuko boxes that Felix saw in the parking area of the apartment complex are intended for this purpose. Modern boxes are equipped with 6A (or 10A) fuses with a timer. This timer is not for controlling the electrical consumtion during certain tariffs, instead it is used for setting the departure time so the heating starts in due time.
The tradition with eletrical preheating in Sweden results in the fact that the infrastruture for everyday charging of EV is already built in many places.
The picture below is from a Swedish Driving School. The new driver learns that a cold engine consumes more fuel and pre-heating has a positive effect when temperature goes below +15C ! The new driver also learns that heating shouldnt be connect too long time to minimize unnecessary electrical consumtion.