To learn about art, you have to work with a variety of strategies. You can search by artist, title, subject, medium of the work, the style of the work, the period and place in which the work was made, or anything that the art itself references (could be another time or place). All of these strategies might not be relevant to your selected work of art and that's ok.
The style - how they used the principles and elements of art - media (materials), and subject matter can all be clues to what people of a certain culture thought was important in their world and what they thought was beautiful. Use the vocabulary of formal analysis - line, color, texture, space, shape, rhythm, unity, balance, etc. - explain how the cultural context of a work is translated into visual art.
Images from http://splitcomplementary.blogspot.ca/2012/08/new-and-improved-elements-and.html