Calendar choses graphics for the selected task based on context

recently calendar began to display context-related graphics in the details/edit view of an item in the calendar. i was wondering if the logic for that was purely done on the respective local nextcloud install or if the php makes any outgoing calls. since i don’t have admin privileges on the system i can’t really trace the flow of data when it comes to the backend.
such graphics would be something like /apps/calendar/img/illustrations/personal_trainer.svg or /apps/calendar/img/illustrations/doctors.svg
so far i could not find out which php scripts call the apps/calendar/img/illustrations/ directory.

does anyone have insight on that?

sorry if this has already been answered. i couldn’t find anything on it via search.

It’s only done client-side with some Javascript.

Logic to determine the illustration is here: