If they are cartons of something heavy they might be packed with a packing material. So say each carton has something dense in it, packing material would fill it and make each carton less dense.
Or the picture could just be about showing a partially filled trailer that indicates business isn't so good. Yeah, yeah, I know the whole truck may have been full and several stops have emptied it out, Or it could just have been taken at the beginning of the loading of it. But we could just be looking at a metaphor for business isn't so good.
KEK!!! That WOULD be great
Be. Sure. To. Drink. Your. Ovalteen.
That is great! Thank you anon!
Or find the roll 1 of 4