I do quite a bit of driving, the majority of it on an interstate. There is a marked difference between driving in town and on the highway and each has its own risks - speed and lane drifting on the highway, and oncoming traffic, stops, lights, pedestrians, sharp turns and lane drifting in the city.
A glance at the dials for the radio or the heater is generally no longer than a glance at the rear or side view mirror. A “glance”, I would submit, at the phone is going to be longer, and if there is anything there, far more likely to be a distraction that a safety “look” at the mirrors. And with the exception of a new car, most people can operate a phone or heater with only a long enough glance to get one’s hand in place.
So, yes, there is a difference; it is in the amount of distraction caused by looking at the message/note on the cell phone.