yeah, not pro style surfing, he keeps his arms much lower which leads to less aggressive arm swinging and a more relaxed look. Sometimes he is using the same pro technique eg. the bottom turn off the lip combo starting at 1-20 is the backside "waitress tray carry" - leading hand has palm facing forward (because arm is low) then it raises up, he looks down into the trough as his board comes off the lip and his trailing arm elbows back into the wave to provide some extra torque. The slow motion smooths it out, but it is probably smooth and full speed.I've been moving in the opposite direction to arm waving- trying to do less on a wave, be more patient and do bigger, fuller turns.
I like the way this kids surfs, very simple but every turn is really framed up by classical body positioning.
There is at least one other backside combo example where he uses the trailing arm elbow/swing to fascilitate this, however sometimes he manages it with his style of putting his trailing hand in the wave face and keeping it there without any swing, which means he must have optimal body positioning to come off the lip nicely.