When somebody is talking to us, if we are not looking at the person who is speaking the speaker thinks that we have no interest in hearing him or we have no respect for him. At the same that is a way for the person hearing, his dissatisfaction with the issue that is being dealt with or the way it is being dealt with. When you are telling something to your assistant and he is looking at some other place and not giving enough attention means he is not happy. These are very well known facts and many times we also follow this during discussions.
This is true in the case of even children also. If a child is not liking the things we are asking them to do, he/she may not attentive, we should understand that that kid may not perform the task well. So we have to change our way of expression and see that he/she will get interested in the task. WIthout interest when we perform the job, the result will never be as expected and up to the mark.