The term “residency” was defined to mean tradition notions of “domicile”.
Meaning that it is the place you intend to always return to, and you retain it until you establish a new domicile.
Accordingly, the court said that for residency you need (1) physical presence, and (2) intention to stay. And you need to have that status for the residency period.
Thus Rahm Emmanuel was a “resident” of Chicago since he had been (1) physically present, and (2) intended to stay and return; and this status had been true for 1 year.
However, there is only one definition of “residency”, there is no other way to also be a resident.
So that means that to be a “resident”, you must fulfill those two things. So if you are physically present for any amount of time but don’t ever have the state of mind of intending to stay and always return, then you are not a “resident”.