I have argued many times before here that design work on small screens is difficult. It is OK to fix typos in a presentation on a tablet or phone, but the small screen is not the right interface to focus your creative energy. This was the reason that my presentation design app SlideMagic launched as a web app rather than as "mobile first".
The issue is not constrained to graphics design. Recently I started venturing in iPad apps that aim to be perfect replicas of ancient analog synthesisers. The Moog Model 15 iPad app is a technical wonder by packing so much sound in a small device, and offering a graphical user interface that enables you to connect wires everywhere.
Keith Emerson in front of a Moog synthesizer (image from WikiPedia)
The problem is the lack of screen real estate. You have to scroll constantly to go from one end of a wire to another. You cannot get the full picture of what you are doing. An I think that the experience would not have been much better on a laptop either, still to small. You need a very large monitor to get the same experience as standing in front of the actual instrument.
This goes further I think. Laptops, and before that, crappy 768 pixel, 80x25 character monitors were big contributors to the design mess in business presentations. A big empty white board works better to design charts than a small A4 piece of paper.
For good design you need a big canvas, and my prediction is that technology will evolve, screens get better, thinner, crisper, pencils and style get closer to the real thing, but if a user interface stays physically small, it cannot beat the blackboard.