9S watches Akechi with a certain intensity as he leaves the room.

...Why did he do that? He had the device right on him. What was the purpose of pretending to get it from the other room?

Despite realizing this, he doesn't say anything as Akechi presents it to Akira. He simply watches to see if Akira notices himself, which doesn't seem to be the case.

You're the doctor, Akira.