What is the Sunnah regarding the sitting posture of a Muslim in the mosque while awaiting the establishment of prayer, and should he sit cross-legged or not?

Al-Nawawi mentioned that all postures of sitting and reclining in the mosque are permissible as long as no private parts are exposed and legs are not extended in the presence of people. Evidence for this permissibility includes the Prophet (peace be upon him) reclining in the mosque with one leg placed over the other.