I mean, in this case, it was a usecase that wouldn't really exist without AI, since they'd just do a verbal description of what they were going for without the image. No one would pay for a hypothetical high quality concept art for a band that has no members, used to potentially hire a member based on vague vibes and a ONE-style doodle wouldn't work.
And also the people who dislike GenAI and think the chapter was centered around that. AI is like politics, everyone with an opinion about it is extreme to the point of being obnoxious regardless of what stance they have.
The international music industry has genuinely ridiculous levels of connections when it comes to other talents and photographers.
before GenAI was a thing record labels had extensive collections of photo's of popular bands and magazine covers and promo's that they have produced for other talents. the verbal descriptions of the role they want someone to fill would be presented alongside photo's of existing groups they are trying to emulate. as such, the use of GenAI was redundant, it didn't fill a usecase that "wouldnt really exist without AI", it just made it extremely obvious they were marketing her appearance after seeing her.
the inclusion of it in this chapter is rather likely a dig at how companies are quick to make their staff use AI even when it's not useful. This is quite common right now in japan it appears, though it doesnt make as big a headline as we see over in the US. It is still a factor of the chapter, just not the main one.
Yazawa expression first turns at the manager mentioning she wanted to contact her only after seeing her face, despite how well the conversation was going earlier about the music. it turns again at being shown how they planned to market her appearance as part of a themed group, something removed from her music and the AI was simply the means the manager used. thrown away easily because the manager doesnt put any value in it either. catalogues of reference materials would be treated far better than that, as they would be filed away to bring out again later.