To put it simply - artists rarely use symmetrical balance in their work because it is boring. When something is perfect, it soon becomes boring to look at. This is why artists generally opt for something weird and unusual, and asymmetric, because it draws your attention to it more easily than symmetry. Other ways artists can create a visually appealing composition is by using complementary colors, for example, or shifting the center of a painting to the sides, or using negative space rather than positive, etc.
The verb dictate means to give an order that must be obeyed. From the excerpt, we can assume that the words duty, honor, and country should be our guidelines. The ideas behind those words must be followed, for they tell us what we ought to be, what we can be, what we will be.
The verb dictate could also mean to speak or read to a person. In this excerpt, however, that meaning does not apply.
"What was the best holiday ever for you?" might work
