If I'm reading this post right: What is the effect of airfoil thickness on aerodynamic lift?

• Airfoil thickness increases the lift coefficient.

And from here: What are the effects of the Boeing 787's very flexible wings?

• Wing flex reduces wave drag.

I'm wondering about the how. My theory is that the air sees a thicker airfoil in a flexed wing, without actually building one. Is that assumption correct? Or is it related to a winglet effect?

Front view of a flexed wing. Orange indicates that perceived increase in airfoil thickness.

If I'm reading this post right: What is the effect of airfoil thickness on aerodynamic lift?

• Airfoil thickness increases the lift coefficient.

And from here: What are the effects of the Boeing 787's very flexible wings?

• Wing flex reduces wave drag.

I'm wondering about the how. My theory is that the air sees a thicker airfoil in a flexed wing, without actually building one. Is that assumption correct? Or is it related to the end-plate effect?

Front view of a flexed wing. Orange indicates that perceived increase in airfoil thickness.