That isn't actually the manager, though; it's confusing, but deep inside, its heejae's own past guilt and form of loneliness. The manager played a part in making this form, but Garam also contributed a lot to it. It's a form that reminds Heejae that he can't love anything else but music, that he is just a damn blade meant to hurt others. And these past experiences made this form stronger, clearer. What he sees right now isnt the manager, but Garam. he only sees Garam rn, but his past of hurting others is haunting him, reminding him- he only knows how to hurt.
No, that didn't look like his manager- in fact, Heejae only remembers his manager's presence (which was as comforting as Garam's), but Heejae doesn't remember what he looked like. i am not saying, that lingering presence isn't his manager; what i am saying is that form isnt just his manager, its garam as well- infact, it is formed by everyone who loved him back but he made them suffer- its a form formed by his lonely soul, to comfort himself -to warn himself, that he should only love music, that music is the only one who accepts him as he is. in that performance, he saw garam- and only garam, the one who accepted him- because, deep inside he believes garam wont leave him (like everyone else). in the upcoming ch, this form will appear multiple times, but dont think it as the prescene of his manager, think of it- as a prescene formed by his past experiances.

bro i genuinely hate how the manager keeps showing up like idk