A character is more than the sum of their parts. But let’s start with the parts. The parts are just sensory representations. This image, this voice, this color all on a flatscreen, whatever. Maybe it’s a word. There’s something that we’re perceiving as audience that represents the character for us.
Now ultimately, the combination of representative elements doubles as an icon for the character. You want it to. Inu-Yasha wears red. Sonic the hedgehog is blue. Harry Potter has round glasses, that sort of thing. And then, when you change that character’s affect by removing some of the elements, something very special happens that I think most storytellers take for granted.
The viewer suddenly gets in touch with the extra sum of the parts; the thing in themselves that identifies with the character.
This doesn't work if you do it too early. You have to represent a character a certain way, and then when the audience gets to know them well, they will know the character beyond the concrete elements. Then when you change or remove one of those concrete elements (i.e. Harry’s glasses), the loyal audience member is rewarded with a very primal sensation of knowing that character, and the thing about them that goes beyond the concrete representation. A bystander who doesn’t know the character or the story will likely feel nothing.
The first time I was able to explain this fully, I was watching Pokemon with a group of my cousins, most of them young children. There was a scene where Ash had no hat on, and was wearing a different outfit than his usual Pokemon trainer regalia. I immediately felt a comforting emotional shift in the room among us, a sense of intimacy. the oldest cousin who was in the room is an intensively subjective feeler with the guts to get invested in stories, so I paused it and asked him what he felt when characters changed their look. Sure enough, he validated my suspicions. I told him I thought it was happening because it forces us to connect with the part of the character that is learned within ourselves. It’s a nice sensation, and to be honest, I think we do it with real people in our lives as well, when we change our look or affect.