For example, assume that I view a sunset and that I declare, "When I look at that sunset I feel overjoyed because it deeply satisfies my need for beauty." In this case, the sunset stimulates in me an intensely personal, affirmative and integrated sense of life response. The sunset embodies a combination of characteristics that - when I view them - triggers an emotional response that's rooted in my core evaluations, which in turn are rooted in my needs. In a sense, being in the presence of the sunset constitutes my kind of experience, one that resonates with my soul.
When another person declares that some specific thing satisfies his or her need for beauty, typically I guess that the response involves the same principle.
Note
1This definition, while strictly mine, evolved in ways more satisfying to me with the help of the following sources:
• the discussion of art that Ayn Rand presented in her book, The Romantic Manifesto
• the reconstruction of Ayn Rand's esthetic and literary philosophy that Chris Matthew Sciabarra provided in his book, Ayn Rand: The Russian Radical
• various of Marshall Rosenberg's discussions of the nature of - including the stimuli and causes for - emotional responses, especially in his book, Nonviolent Communication: A Language of Life.