Accordingly he too must distribute his attention to all those present so that each of them believes that the lesson is addressed to him personally. The latter of course is not always true. And this is because the teacher inevitably turns his preference towards one or more of the people who make up his audience. The reasons that lead him to this are not so interesting although most of the time they are related to he expects from the particular people. But the bottom line is that if they didn't exist the lesson might not have breath. Because the monologue could not be turned into a dialogue even if it is often silent.
The presence of the few makes the lesson more efficient and interesting for the many. Returning to the theatrical analogy it is the presence of some particular person that can one day make the actor surpass himself. On the other hand the existence of the many and therefore of the e-commerce photo editing course allows the presence of the few and therefore of the quality level of the course. I would even venture to argue that the presence of the few ultimately helps pull the rest toward improved performance. But just as the teacher cannot be depersonalized the students cannot be depersonalized to the same degree.
The teacher does not have one relationship with a set of twenty students but twenty relationships with twenty different people. The special interest the special anticipation and the special demands towards a student do not deprive the rest of the corresponding feelings. The teacher himself through a little experience will readily perceive two things. First that almost until the end of the lessons he will not be able to exclude the sudden jump of a student to a separate level of quality. Which makes a lot of sense since many assimilate at slower rates and perform with a delay.