I don't think this is a good example. The bus is clearly a simplified representation. If the answer/explanation given was actually correct then you'd also expect the bus to have other details like side view mirrors.
Edit: I hate to dwell on this too much, but even if a door and mirrors were visible, the bus could be in reverse. This seems to be more of a case of accidentally picking the intended answer due to a lack of knowledge. (Of levels of abstraction in representation and of vehicle design.) That said, I don't necessarily disagree with the underlying point being made.
Edit: I hate to dwell on this too much, but even if a door and mirrors were visible, the bus could be in reverse. This seems to be more of a case of accidentally picking the intended answer due to a lack of knowledge. (Of levels of abstraction in representation and of vehicle design.) That said, I don't necessarily disagree with the underlying point being made.