Who Perceives What?
The debate over the argument from illusion is quite extensive, already. Whatever your stance on it it’s an interesting one.
I'm not sure I see the problem. If you and me are next to each other and we are looking at the Empire State Building, I can point to it and say "that's the Empire State Building". I can only assume - all else being equal - that you will see something very similar to what I see. There's no way to literally get into somebody else's head, but, daily experience seems to show we see things similarly.
The problem is with the idea of sense-data. It leads us to believe we are not able to see the Empire State Building, only the sense data. JL Austen states it like this:
“The general doctrine, generally stated, goes like this: we never see or otherwise perceive (or 'sense'), or anyhow we never directly perceive or sense, material objects (or material things), but only sense-data (or our own ideas, impressions, sensa, sense-perceptions, percepts, &c.).”
It’s like saying we sense sense, or experience experiences.
If you are interested in how the brain works, that's the topic of neuroscience and cognitive science. You aren't going to find an entity "the self" in the brain, even if such constructions originate there - with interplay with the environment of course.
I think I may be missing something, or probably am missing something.
Right, there is no self living in the brain viewing experiences and perceptions. So indirect realism is redundant. That’s the basic point.