In brief
The driver can observe the maneuver from the outside with a supported system.
Useful to know
Bosch's Garage park assist is a partially automated function for entering and exiting a narrow garage. The described variant controls gears, steering, acceleration and braking, and the driver monitors movement. [1]
Control from the outside by phone allows the person not to stay in a car with limited opening space. The maneuver only continues when the specified control conditions are met. It's not free leaving the car unattended. Availability, permitted use and exact limits should be checked for the specific model and location.
Sources
For further detail and to check the information: