Architectural details:
The walls consist of metal frames that not only provide solidity to the formwork wall itself, but also offer the opportunity to create a path at the top of the wall with a few scaffolding planks. This path is even provided with a handrail with some additional scaffolding planks. The path is useful for the people who pour concrete.
Between the steel frames the dark brown smooth wooden wall is reinforced with wooden beams. All this because the concrete would otherwise push out the formwork outwards and thus the wall would get an unintentionally strange shape.