..................need not be at the equator (for any planet not in the ecliptic and/or having a rotational axis not perpendicular to the ecliptic).
Agreed, but I would think that the rings would rotate around the center of mass.
(But, of course earth’s magnetic forces do not exactly align with our poles.)
They are, it’s just the viewing angle that throws you off.
What I was trying to say is that the rings themselves do rotate around the center of mass, but the photo, probably due to the position of the shadow, makes it appear otherwise.
My comment was only with regard to how the shadow can fall at places other than the great circle under the rings. (In accord with theories of planetary formation, that great circle seems to be the equator.)