Passing is an intrinsically 'other oriented' position. I dress for myself. There is no internal drive for me to try to get a particular reaction from someone else. I believe the fetishistic position is 'self oriented'. (You could say selfish. But that suggests a distinction from someone else.)
Since 'gender' is often seen in contrast with, or to, another person, does someone who is gender disphoric see his or her situation as uncomfortable in the context of how his or her gender is seen by others? ("I want to be seen and accepted in the opposite gender.") Or, how it feels inside regardless of the external presentation. If one listens to the writings on this forum, one could sometimes assume that the reaction a CDer gets from others defines the success of his CDing.
A transvestic fetishist, on the other hand, I believe, derives validation, (and therefore "success"), not from other people but from how he sees himself in the mirror of his own experience.
The recent discussion, on this forum, about RS's use of latex face masks could be enlightening if we see it in the context of someone trying to "pass" as a female vs, someone who is trying to "portray" a female for his own satisfaction.
But,....I could be wrong.