--If YOU had been Mr. 3C in that situation, would you have even been aware of us? Would you have moved seats to avoid reclining into my laptop?
--If you had been ME, would you have asked politely if he would please consider moving seats?
Sorry dude, but if I was in 3C I probably would have no idea that you're there, much less that your daughter is next to you. As everyone's pointed out, you can move 4 feet away and grab one of the other empty seats. With such an empty cabin, I would do that pre-takeoff to avoid precisely this situation.
There is a small chance that I would ask the guy to move, but really I would just move seats myself.