Differences in Art During Different Time Periods

At the Getty, I noticed that there are different focuses during different time periods of art.
   During the Medieval time period, for example, European art mainly focused on the religion of Christianity. In Medieval stained glass, tapestries, and paintings, there are depictions of Jesus, Mary, and the Twelve Apostles. These figures are usually depicted with halos around their heads as a symbol of divinity. The faces of the subjects tend to be emotionless and the bodies tend to lack proportion. With statues and carvings, the subjects were flat, and like all other Medieval art, lacked realism.
   Art during the Renaissance was much more realistic. There were many paintings, tapestries, and statues during this time, but they did not focus on religion. Proportions of the human body during this period were more realistic, but sometimes artists liked to elongate the limbs of the statues of some mythical gods. Perspective is prevalent during this era, mainly linear perspective. The concept of light and shadow are seen in paintings. Art captured the beauty of nature and everyday life.