What does " see behind the frayed facade." mean?
The financial problem was becoming acute. The rent was three months overdue, and the only reason they not been evicted was that the landlady was captivated by Catherine's father and his grandiose plans inventions. Listening to him, Catherine was filled with a poignant sadness. He was still his cheerful, optimistic self, but [she could see behind the frayed facade.] The marvelous, careless charm that had always given a patina of gaiety to everything he did had eroded .