This deadly phenomenon of a victim becoming a willing accomplice in its own destruction is not confined to the animal world. The speaker continues the boa-constrictor metaphor by talking about what happens when economic conditions improve and the industry breathes a sigh of relief. This metaphor creates some powerful images, especially the one of the boa smiling and tightening its grip. The boa metaphor slithers along for several paragraphs. An analogy is another type of comparison.
Analogies are especially useful in explaining something that is difficult for an audience to grasp.
It is easier to understand a concept if it is explained in terms of something you're already familiar with. When I was learning how to use a computer, my mentor suggested that I think of the computer's hard drive as an office with filing cabinets and shelves containing various equipment and material I would need to work with, and the RAM as a desktop where the work would take place. This helped me to understand some things that had been confusing. A fine example of an analogy that's part metaphor is found in a speech by Daniel Webster, one of the greatest orators of all times. Let us imitate this prudence, and, before we float farther on the waves of this debate, refer to the point from which we departed, that we may at least be able to conjecture where we now are.