Now that you mention background, the gear shift lever is high up in the Park position.
Tried to see what position the key was in, but not high enough resolution for that. Plus, IIRC, those old cellphones would run a battery down pretty quick if you did not have the engine running.
IIRC, it was not until Motorola came out with the HandiPhone that we were able to leave the phone 'ON' and a horn relay hooked up.... I was working as an electronics tech in 1969 and a precious few of our company cars had those installed.
They also had a timer on them, that we usually set for "1 hour" and then it turned the phone off. Even those phones if left on for 10+ hours would drain a battery below being able to start the car's engine.