text: For a lot of reasons. It actually depends on the person involved.\n\nFor one thing, it could be because the person is simply restless in nature. People who belong to this category often are found doing other things besides the one that they are currently working on.\n\nAnother, it is probably because it is a habit that one has developed in the earlier parts of one's life. Pressumably the parents of this person is observed talking on the phone with notepads. In an artistic way, this person is incorporating what his/her subconscious has picked up from her past.\n\nStill, it could be that the person is a workaholic. Someone who falls under this catergory cannot simply focus on doing one task alone. For them, though not really intentionally, talking idly on the phone consumes work time. These are the type of people that cannot keep their hands still, and due to the skill inherent to one person, he begins to multitask. Or in this situation, draw.\n\nLastly, it could simply be because the person is simply... uninterested of the conversation and feels the need to do something other than talking idly on the phone.\n\nOfcourse, there are sometimes where in a person is a combination of these categories. ^^\n\nI hope it helps!