This is good design, good taste. See, the first thing is the function of the product, no fancy stuff; it is simple. Principles? Minimalism, focus on people’s comfort to use, a lot of attention to all the details and their harmony, how they resonate together, those little color parts…
There is a nice visual style cinema related to that kind of aesthetic I’d recommend to watch, Play Time – a 1967 film directed by Jacques Tati.