This is going to be a philosophical topic. The simple standard explanation of S vs. N is details vs. ideas. The problem with this is that everything is conceptual. Everything is an idea. Everything is a social construct. Whatever gets into your head or whatever your brain or consciousness detects is filtered into this human programming of how reality is. When you are observing an apple, you are connecting dots of your own. Technically, an apple is no more than just a collection of atoms as everything else is. It exists because the environment and the laws of nature allows it to exist. We don't "see" those physical inter-relationships between the apple, the atmosphere, the ecosystem, and the 4 forces of nature. We're limited to an organ that depends on our detection of electromagnetic radiation---light, and then our internal "software" rearranges the input into a seemingly distinct 3 dimensional shape in front of us. Mathematics and science is our attempt at interpreting this reality more accurately, but they are also interpretations. (Granted enormously better than any other way.)
So what really is S vs. N? It's relative. It's relative to experience. The more "experienced" a person is with an object the more "S" it is to that person. For example, someone who has never seen an apple will treat that apple as "N". Someone who has seen multiple apples, will treat that apple as "S." This is why, if you prefer N, cultures can seem interesting from the outside but boring from the inside. Because if you already belong to a culture, it is experienced already for you. This is why "abstract" concepts like "Justice" and "Freedom" are more "N." Because they are "less experienced." The idea of "Justice" can take any form, and it is impossible to really define the parameters of what 'justice' or 'freedom' is. There is more to experience about "Justice" in order to really be experienced with "Justice." There are also many interpretations and it becomes a blob of vagueness. Whereas more physical things like a bike are more "S" because they are more experienced. Abstract concepts can be "S" too if they are more experienced and less inclusive of interpretations. The concept of "Freedom" can mean something very exclusive and experienced for a person.