He would recognise that it was a deliberately-manufactured artefact.
The accounts of his life and achievements indicate that he would show others, who would be free to make their own observations and notes.
Supposition: the 'phone would be described and archived in the
Philosophical Transactions of the Royal Society, available to generations of scholars
External Quote:
Our
origins lie in a 1660 'invisible college' of
natural philosophers and physicians.
External Quote:
The Royal Society's motto 'Nullius in verba' is taken to mean 'take nobody's word for it'. It is an expression of the determination of Fellows to withstand the domination of authority and to verify all statements by an appeal to facts determined by experiment.
https://royalsociety.org/about-us/history/ -Royal Society website, "History of the Royal Society".
The symbols on the keys would tell him that the user used Latin script and Arabic numerals (in the sense that we describe "our" letters and numbers as such- contemporary Arabic numerals are different to contemporary "European" numerals).
Markings on some internal components would further support this.
He would be intrigued by the tiny lenses. I'm sure he would study them.
If the 'phone was functional, charged and unlocked, Newton would find that manipulating the keys caused the display to change. He would probably find further evidence for the language of the user (or the 'phone's intended user).
He might work out that the battery was a power-source and that the 'phone only worked when the battery is connected.
He
might find that the 'phone could generate sounds, and might identify the components responsible.
If the battery were identified as a power-source, Newton
might have successfully identified connections (even without any assumptions regarding electricity) and deduced that the discrete components within the 'phone somehow manipulated that power to enable the device to fulfil its aims. I doubt if he could have deduced much about the 'contents' of integrated circuits.
And Newton would probably "invent" the Phillips screwdriver.
But we are not in Newton's position.
We have spectrometry, X-ray crystallography, scanning electron microscopy, and people who can use these techniques effectively.
We have the ability to share images of, and data about an artefact on an arbitrarily wide scale if we want to.
We have a much better understanding of chemistry and physics (thanks to people like Newton).
The structure and composition of
any conventional matter, down to the scale of individual molecules (and arguably atoms) can be found if we really want to. Of course, if we found artefacts made of, or including, "exotic" matter, that would point to an unusual origin.
Clumps of slag or bits of wire comprised of alloy which don't have the constituent metal ratios found in a cursory search of US alloy manufacturer's catalogues are not exotic matter, nor do they in any way whatsoever indicate a non-terrestrial origin.
Sorry, Avi Loeb