In Weinberg's book, Quantum theory of fields-II, he talks about a chair in the chapter on spontaneous symmetry breaking. He says that, for a chair, a state with a definite l value is not stable but a state with a definite orientation is. I do not understand what he means. An l state can be disturbed by a very small perturbation. But, for an isolated chair in vacuum, a small perturbation is enough to change its orientation. What is the meaning of Weinberg's statement?