Constant speed propeller angle of attack and thrust?

the blade is twisted to give the same pitch at different radiuseseses.
the twist is something fixed in the shape of the prop blade,

I'm aware of that - by "twist" in this circumstance I mean the total pitch
changes due to the constant speed unit. Rotate - as you have used - would be
a better choice.

What I am confused about is why some texts talk about "taking a bigger bite
of air" as if the PITCH angle is what causes thrust rather than the ANGLE OF
ATTACK. I was under the (mistaken) impression that the AoA was kept the same
over the operating range of the CSU, but have been told this is not the
case.