Maybe the kid wants to feel grown-up and independent.
It could be that the cartoon kid has a specific goal or dream that requires money, so they're seeking a job to achieve it. Or perhaps they just want to gain some experience and learn new skills.
Maybe the kid has a curiosity or needs help with something.
It could be that dinner is ready, or the weather outside is turning bad. So, the mom wants the kid to come in. Also, perhaps the kid has been out for too long and it's time to rest.
Maybe the kid has been up too late and needs to get enough sleep for the next day.
It could be that the kid saw a cartoon advertised at that house and wants to know more. Or perhaps they're friends with the people there and know they have cartoons to share.
The cartoon of a bald kid can be funny because of its unique appearance and the comical situations it gets into.
The father might start by simply stating what the job is and then try to explain why it seems pointless to the kid in a gentle way.
Maybe they're having a fight or competing for something. Kids in cartoons can act out for all sorts of reasons.
Maybe the kid ate something bad or got sick. That could be the reason for puking.