I'd argue that the way we define "state" as being "a set of things that matter to us". In the context of the article, if we define state as being a "state vecto

I'd argue that the way we define "state" as being "a set of things that matter to us". In the context of the article, if we define state as being a "state vector of (hours, minutes, seconds)" we explicitly exclude everything but these three value (miliseconds, date, etc). The two pictures with the hands pointing to the same umber then by definition are the same. We can even consider them as being the same "every 24 hour". The distinction between single threaded or multi threaded is moot; the world is in perpetual mutation anyway; even is two lines of code are being executed at exactly the same time in a multithreaded fashion, one is executed on CPU A and one on CPU B so their "environment" is different and there will never be two lines of code that are executed in exactly the same environment - regardless of what tools and techniques you use to try and enforce reproducibility. What matters is to explicitly define what you consider as having an impact (which you add in the "state") and what you don't (which you leave out).