Yes and no. There is an idealistic aspect of it. Si is said to ascribe almost mythological feeling or definition to objects, like a clock or a train, not entirely differently than Ni, but Ni is aware that the thing is a symbol and attempts to deconstruct it and break it apart. Si on the other hand kind of...feels the symbol...for lack of a better word than feeling...they don't try to break it apart necessarily. The pink jacket is more than a pink jacket (which is what Se would see) the pink jacket represents a mood, a memory, a feeling, a thought, a way of being ...something intrinsic in the person's personal, subjective map of internal sensory impressions.
The Si mind is more linear and has a mind like a filing cabinet, collecting stored facts and past experiences. Si carefully studies new information before accepting it, because they have to process where it fits into their mental files. This can make them skeptical, or want to see proof, or be hesitant to debate without facts.
Si doesn't necessarily notice all details in the environment, though. They're just good with the details of what they care about. Si doms value depth of knowledge over breadth.
They also don't necessarily value broad social tradition, just the things that are meaningful specifically to their Si. Do you understand the difference? Liberal SJ isn't going to adhere to cultural conservative traditions just because they're SJ. They're going to adhere to what is meaningful in their own experience, their own past, their own family, etc.
Si doms also tend to be sensible, careful, and concerned with maintaining health, safety, and security.
Here is some evidence of Si in myself: I can cook certain things without having to follow a recipe, I just know this will be too much, etc. I have irrational emotional attachments to certain objects: my pink abercrombie hoodie, my pillow, etc. make me feel safe. I need some semblance of continuity to feel completely at ease, although I crave change and novelty.
Simulated World gave me this beautiful example which really resonated with me: An ISFP (who has Se) on the show Freaks and Geeks says she wishes she had never heard the new Greatful Dead album so she could hear it again like new, as though it were the first time.
A person with Si, on the other hand, would enjoy listening to music they deemed beautiful over and over again, gaining something with each time they listened. They don't have the same impulse like "oh I want to hear this like I've never heard it before." Part of the enjoyment of the experience comes from the sense of knowing the piece of music, having feelings or memories associated with that music, and discovering new things about it.
Here's something I posted last night in another thread about Si (sorry for any repetition):
Si is a subjective set of internal sensory impressions. Some examples of Si working in the real world, "This food doesn't taste right." You can cook (hypothetically) because you remember seemingly instinctively how to make your favorite meals without a recipe, and know exactly what is "missing" by tasting what you're making. You can tell if something is "off" and doesn't taste the way you know it "should" taste.
Or the picture is crooked. Or this film doesn't align with your particular standards of aesthetics. You may have a very particular preference for how music should sound or how art should look, or a particular flavor of wine you always drink.
You may also store past experiences and facts kind of like a filing cabinet in your mind, and retrieve them in a linear fashion.
Mostly though, Si is an internal set of subjective sensory impressions. It is not the same thing as strength of memory though it does rely on past experience.
Si doms may take great pleasure in knowing every single little detail about their favorite subject or chosen field. They will hesitate and examine new information carefully to see how it aligns with their internal filing cabinet data base.
Si can concern itself often with things like health, safety, and security.
Si related neuroses may manifest in the form of either A) fearing things will always be repetitively the same OR B) conversely, things will be an out-of-control threat to your safety/security/familiar way of being.