One reason renaissance art looks more lifelike than medieval art is that it uses
ordinary objects.
naturalism.
perspective.
classical influences.

I would go with classical influence.  Just like philosophy and literature.  Renaissance art was influenced by Greek and Roman cultures.  Apart appreciating the human form, it also revealed qualities of remarkable imagination as well as its dedication to religion.  The best examples of Renaissance art were Michelangelo’s La Pieta and his statue of David.

answer: the feeling it gives you when you look at it.

explanation:

in every single medium of art, you are supposed to feel something that makes it art. like how a song can make you cry, or how a photograph can make you nostalgic. art is very important for expressing yourself as well, when you are happy, sad, depressed, or angry.