“Which manipulations can be done to a TTG photograph” is largely determined by whether the manipulations are “light”-related or not.

In TTG photographs:

A. After exposure, “light”-related aspects (tones and colors) must be changed if the way they were recorded misrepresents the scene (per P7)...

— but —

B. After exposure, non-“light”-related aspects (forms and shapes) cannot be changed — except in a few select ways, as per P2—

. . . not even when changing forms and shapes would make the photograph “look more like” the scene depicted.