Every animation should answer a user question: "Did that work?", "Where did that go?", "What should I look at?" If it does not answer a question, it is decoration and probably a distraction.
Strong answers cover purposeful animation: providing feedback (button press states), showing spatial relationships (page transitions), guiding attention (loading indicators), and delighting users. Best candidates discuss performance implications, reduced-motion preferences, and the principle that motion should communicate, not decorate.
Tests design craft and restraint. Junior designers often overuse animation. Senior designers use it purposefully and always consider the prefers-reduced-motion media query.