[Theory] Ayu and her art director...

[truehappiness]

But wait a second, didn't Kazuyoshi take the pictures? What exactly do these people do? They choose the images that are used for covers and booklets?

They design the covers/packaging and retouch[?] the images, I believe.

Ayu chooses the images in the end, but the ones who are in control of art direction/design are the ones in charge of the final product, I guess.