To me art at its core is a work by a person that communicates the subtleties of some idea or experience. The best art for a given person might evoke the strongest feelings because it speaks to them about something they now understand better, even if they still couldn't articulate it in words.
From the lens of what the artist chooses to highlight, you can make inferences about what is important to that person, and from a wider perspective what artists choose to highlight can reveal more about a culture.
