Not read exactly what he said, but he may have a point.
A phone is something you can have on you all of the time, use while you're walking, sat down, on the train, wherever - maybe using on-the-go is the definition of mobile?
An iPad is something which you could easily carry with you everywhere in a bag, but which you're unlikely to be using while walking down the street - its portable, certainly, but not mobile?
A laptop is something that you can really only use if you have somewhere to put it, as opposed to an iPad which you can use while stood up - maybe we call that relocatable, if we want to distinguish it?
So, the words probably aren't important, as the definitions in the English language aren't specific enough to mobile devices to say absolutely one way or the other. But the concept that some things you can use while walking, others while stood up but stationary, and yet others only while you've got something to put them on, is certainly valid.
David
