The left panel is what every AI code assistant generates by default: a class hierarchy. NotificationService, EmailNotifier, SMSNotifier, PushNotifier, NotificationFactory, UserPreferenceManager. The AI reaches for classes because that is the dominant pattern in its training data. It generates more code because the class architecture requires more machinery: constructors, inheritance, factory methods, dependency injection.
The right panel is the same AI, given the same task, prompted differently. It generates pure functions, typed dictionaries for configuration, and a dispatch map instead of a factory. Fewer lines. No classes. The same behavior, expressed directly.
The AI is not the problem. The training data is the problem. How you prompt it changes everything. The exact prompt that produced the right panel is included with every copy of the book.