This image is powerful for the onlooker because the dust and fumes from the massive truck automatically make you stop breathing in an effort to avoid inhaling what isn't actually around you - similar to the "ouch" when you see another person hit their head. This feeling is known because it is experienced by everyone at some point, such as walking along the sidewalk when a car expelling a smelly dark cloud passes by. The accompanying text proves that the dust and fumes are even worse than initially assumed; it gives the reader a sense of both sadness and despair.
