Iris comes from Greek, named for the goddess who carried messages between gods and mortals along the rainbow, and the name is traditionally associated with communication and connection across distance. It's often read as suggesting someone who bridges different worlds rather than staying fixed in one place.
The comets should be used when they appear and in what they rule; just as fixed stars, they have to be used according to each one's nature. - Picatrix (Andalusia, ~1000.AD)