Sitting cross-legged in Buddhism means sitting cross-legged.
The historical facts in the TV series "Da Gong Ming Ci" are not very rigorous. There is no need to be so serious, is there? In fact, this scene can also be understood as Wu Yousi in Fu Biao is a clown, so he just sits cross-legged, while Taiping in Chen Hong feels very relaxed in the face of Wu Yousi, and he just sits cross-legged.