'Ai's work with spatial form has its roots in his furniture, albeit on a smaller scale. Here, form is consistently geometric in terms of each of the several elements of which it consists: circles, ellipses, rectangles and squares, and by extrapolation, positive and negative cubes and spheres... The visual perfection of all these forms leaves a lingering impression. Theres never any clutter; nothing is overdone. At times, the air of perfection is almost too much. But there has always been an edge of humour in Ai's work that is never quite permitted to descend into cynicism, a wry undertone that is its saving grace'
(K. Smith et al., Ai Weiwei, London 2010, p. 101).