Although plasterboard is cheap, it is still suitable for elegant, upscale living spaces like the one in the picture. Because it is professionally installed and covered, you cannot see the surface and can only guess what kind of wall the television is hanging on.
If you are wondering how the lightweight wall holds the heavy furniture, let me tell you that large panels are often screwed to a wooden substructure to ensure stability. Devices or chests of drawers can be securely attached to the wooden structure. Of course, the lighter devices can be secured directly in the wall with cavity dowels—provided the sheetrock is of appropriate quality.