Ra's shutting his eyes and accepting his fate?
The very essence of Ra's is his perennial attitude towards his goals, and his life. Would he just entirely give up because a student outsmarted him? Doesn't sound much like a leader to me, and I'm pretty sure the members of the LOS would give their lives for him for good reason. He would find a way to escape, to endure and to continue his mission. That's the character Dennis O'Neil created, and the reason why Ra's quickly rose to the status of being one of Batman's greatest foes.
I interpret that scene as Ra's acknowledging that Bruce had played a winning hand. But at the same time, with his mind set on the mission, he would find a way to escape to fight another day.