The tower has a tail, a ribbon wall that unwinds around the edge of the site, protecting it from its neighbours, but without being hostile to them. It bulges open at one end to provide access down a flight of steps into the basement. The finish for this tail is remarkable. A skin of living green moss sprouts through square blocks to create a vaguely Aztec pattern. This gives a clue to what the building, with its multilayered references to natural materials and organic forms, is about. Its material qualities, which range from rough to smooth and tight to loose, give the building its distinctive character.
The tower has four different types of glass: some flat and transparent; others, in the changing rooms, etched for modesty. Some windows push outward, while others are sucked in, as if the building were breathing. The same themes shape the interior. The ceilings are perforated metal, into which a series of larger black holes has been inserted, drawing the surface smoothly inward to make way for the lights. In the corridors, the lights go the other way, marked by dollops of silicon gel bubbling outward.
If the exterior is wet and mossy, the interior demonstrates an almost perverse interest in mixing hairy surfaces with viscous finishes. Some display racks are sheathed in pony skin, others are coated in silicon. There are display tables in molded see-through fiberglass, and some are filled with fiber optics like jellyfish tentacles.
In the basement, the floor is the same raw oak that Herzog and de Meuron used for Tate Modern. But on the upper levels the floors vary between lacquered steel for stairs and a vulnerable ivory-coloured carpet that even the infinitely careful and patient Japanese have trouble keeping spotless.