Perhaps the dog in the cartoon has a restless expression or is shown looking longingly through a window, leading you to think it wants to go out. Sometimes, the way the dog interacts with its environment can give that impression.
Maybe it's because the dog is constantly looking at the door or pawing at it.
I think Helen does think that. Maybe the dog was barking or looking towards the door, which made Helen come to that conclusion.
The dog could want to go out because it smells something interesting or sees other dogs playing outside and wants to join them.
It could be for various reasons. Maybe the dog is trying to play or catch something.
Maybe it's a power outage or a technical glitch. Sometimes in cartoons, these things happen randomly for the plot.
Maybe it's bored and wants some adventure outside.
Maybe it's for a comical effect or to show extreme surprise.
It could be because the creator wanted to highlight the common emotions that dogs might experience in certain situations. Or it might be a way to make people more empathetic towards their pets.
It could be that the crossed-out cartoon dog was an error or no longer relevant to the overall design. Or perhaps it was part of a symbolic message that we need to interpret.
It could be that the dog was following a scent or a familiar person. Or perhaps it just had a random urge to explore in that direction.
It's possible the dog went south because it heard a familiar sound or smelled a familiar scent leading that direction. Maybe it was on a quest or adventure of some sort.