Here are some dark and blurry photos at one of the private views (thanks, Hamish).
It's a curved timber shell with lights embedded in the polycarbonate panelling. Timber structure is designed as hundreds of interlocking pieces, the result of much clever mathematical head-scratching by Arup's engineers Martin, Lip and Hamish. The timber staining looks strange, and the doors seem tacked on like a desperate afterthought, but the structure has a great shape, crouching like an insect, and is larger than it seems from the outside. It looks better at night. The lights each have their own trigger (a combination of charge-already-saved and light-level-detected?), so they come on at different times.