Si is about your impressionistic, internalized view of the sensations. They don't merge with their environment, they want to be at peace with their physical self, ergo they would be more concerned with relaxing sounds and imagery.
IMO intuition hardly interacts with the environment at all. I have said in the past that intuition deals in "pure, refined information," but others have countered saying that this would make it based on principles whereas Ni-users say they have dealt in vibes. Vibes are information, though. They aren't interacting with the environment as can be seen through the senses.
Think of it this way: Noun:verb::sensing:intuition.
N is about what is done, observing changes to differentiate information.
S is about the props, players involved, and what they physically are.
So S isn't about "scratching the surface" and only seeing "what is done, without concern to how." Intuition deals in changes, the way I see it. Some aspects of Sensing might actually be harder to define because a color, for instance, cannot be understood until one has seen the color before. It can be described, but it takes S to experience it. All that stuff you heard about Si being dogmatic is from butthurt ISFPs who think they're INTJs.