I know that "If you were able to look at the back of someone's eyes, there would be an upside down image." But I don't think you meant, "the part of the brain controlling movements and sensations in the rest of the body is upside down..." No part of the brain is "upside down".
But I don't agree that "there isn't a little person inside your head watching it on a cinema screen." Yes, I agree that "All there is, is...your brain processing what you see so you can make sense of it..." That is the little person.
It is important to recognize that "little person". That is obviously an analogy, but "you" are in there, and we are talking about "cognition", so here is why it's important to recognize that "you" are in "there":
Let's break down consciousness: Sensations come from the sensory organs, and at the point where they physically end inside the brain, a connection is made in consciousness called a "perception". Perception is not the "sensing", as many people incorrectly believe; it is the mind's acknowledgment of having received sensory inputs. There is a form of blindness in which the eyes and the nervous system work perfectly--nothing is organically wrong. But when the sensory input reaches the brain, no perceptions are acknowledged. In other words, there is no "perception" of having had the sensory experience.
After a perception, which is the acknowledgment by the mind of having had a sensory experience, then the perception goes through at least one, and often more, stages of cognition. The first is a simple induction: "Oh! Something exists!" Perceptions are the acknowledgment that "something" exists. The next stage is to "abstract" from it the information that will eventually tell us "what" exists.
Knowing "what" exists is the field of metaphysics; so the first conscious stage of abstraction is to determine "identity". But the first mental function after perception isn't the abstraction itself; rather it is the process of epistemology that allows for the abstraction. Otherwise, it would be like saying we extract oil from the ground without an oil rig.
The abstraction of information from our perceptions is said to be "intuitive". Cognition is "a. non-propositional apprehension (perception, memory, introspection, etc.)...
Intuition is a "result from the proper species, or the proper image of the object itself, impressed upon the mind by the object...",
and "quidditative" means "that which arises from the proper image of an object, like intuitive knowledge, and besides, penetrates distinctly, with a clear, proper, and positive concept, the essential predicates of a thing even to the last difference." http://www.ditext.com/runes/c.html
In order for the mind to make sense of its world, it cannot look down at its feet and see them as being above his or her head. If the cognitive mind did not turn things upside down for us, then to see ourselves in a full-length mirror we would have the image that children have of people below the equator standing on the earth upside down, and even the earth there is upside down---until you turn the picture over.
Not being a neurologist, I do not know in which part of the mind our cognitive processes turn things over from the way they appear at the back of the eyeball. You do not appear to be a neurologist either.
And while I see that this question is a philosophical premise to be figured out, it must first be determined by such scientists as can know where in the brain, and how in the brain, the process is done.
Only after science gives us the answer can general philosophy determine the truth or falsity of the statements, because that is the purpose of general philosophy.
Cognitive neurology is specialized, and you need to ask one of them-----unless of course the answer is already out there and one of us knows that answer. But don't count on it.