In this chapter, we largely focused on the RecyclerView and how to make it work even better within your application, and especially for overview/dashboard screens. Changes such as adding the dividers and animations don't change the functionality of an application, but they do change the user experience. In this case, they make it easier for the user to understand the screen and easier for them to understand what happened when things changed.
These sorts of changes can be seen as "polishing" the application. You can build the application without them to ensure that everything works, and then add them in afterward. It's a good idea to slowly build a list of generic structures that can be used to quickly polish any application. A good example will be a generic ActionCommand to use the DiffUtil and apply the changes to an Adapter.
In the next chapter, we...