The MacOS takes care of the former, while the industrial design of the iBook or iMac covers the latter. Remember that looks represent much more than you think. When you go in a store and choose between products, shape and appearance often influence you, especially if you think that both products can serve you well. This is why they always give their products the best possible presentation. Choosing a product can even be said to the same process as choosing a mate.
Some people choose personality, some choose physical attractiveness.
Some care about both. The computer buyer who cares only about RAM and hard disks when choosing their computer is analogous to the person who wants a soul mate rather than the perfect body. The truth is that the masses care about looks first, though. Most people out there ask someone out because they like what they SEE and want to get to KNOW the person behind the attractive body. In the same way, most consumers who want a computer will react positively to the industrial design of an iMac or iBook and then will want to get to know it better.