My analogy is teaching.
When teaching someone something you have to work quickly and keep the person engaged. If you have irrelevant details or go off on tangents you will lose the person. But, if you keep the person actively listening and interested in what you are saying they will pick up what you are teaching them faster.
Last summer I taught English at summer camps throughout Italy. It was challenging to keep 10 Italian children’s attention when I don’t speak Italian and they speak very little English. I learned that by keeping them active and having short lesson plans I could keep their attention and interest.
To say the least, Poundstone’s E-lit piece keeps your attention. The words and unrelated symbols are flying by so quickly that you are constantly having to process what you just saw and yet pay attention to what is next. Just as in teaching, you want to continually be changing topics so that you are keeping their interest. But, you don’t want to move as fast as this E-lit piece does because then you will probably leave your student in the dust.