Marshall McLuhan is credited with this line from Understanding Media in 1964, though he was quoting his friend John Culkin, who was summarizing McLuhan. The attribution is therefore slightly tangled, which is appropriate for a thinker whose whole argument was that our tools rearrange the arrangements we thought we were making. He published in 1964 and, on most days, is still correct.

The sentence describes a loop most people prefer not to look at directly. We design a tool for a purpose. The tool does that purpose, but it also changes the hands that use it, the habits of the user, the rhythm of the day, the shape of attention. The printing press did not just distribute text. It rebuilt the reader. The phone is not just a device. It is, quietly, rebuilding the nervous system of the species holding it.

A cat bringing its nose directly against a lit phone screen is the loop in miniature. The cat did not invent the device. The device has entered its environment, reshaped the available surfaces, started glowing, started buzzing. The cat adapts. It sniffs. It occasionally bats at a notification. We tell ourselves we are more sophisticated than the cat. We are holding the same device. The difference, if there is one, is that the cat does not pretend it is in charge.