clever design for a truck and trailer matched set, the truck slides into and out from the trailer, by Citroen

This particular variant of the H-van does have some attempts made to be stylish, as it was designed by Heuliez, a French coachbuilder that made a number of H-van-based (and other Citroëns, too) special editions like ambulances and other sorts of vehicles.

https://www.theautopian.com/this-slide-in-citroen-pickup-to-some-other-kind-of-truck-is-deeply-cool/