some of the most easy-to-“read” works are those rooted in christianity, as it played a major part in the formative stages of western art. this was due, in part, to the fact that many of the people who commissioned work did so for a religious purpose. i myself am not religious at all, but it is vital to understand the importance of works like this in the development of art. without wealthy religious patrons, some artists would never have created any work at all, and culture would have suffered greatly.
the “merode altarpiece,” or “annunciation triptych” (triptych= three panels, diptych=two panels) is one of these commissioned pieces. it was created in the early to mid 1400’s by robert campin, “the master of flemalle.” it is uncertain exactly who commissioned the work, but it is known that they are the couple represented in the left panel. (usually, the person who commissioned the work had an impact on the content of the painting. one good example of this is a series of paintings by peter paul rubens, commissioned by marie de’medici. because “medici” means “doctor,” the artist incorporated medicinal fruits in the paintings to represent medici’s family. see the upper left corner in “landing of marie de’medici at marseilles”– the fruit are displayed in a circle.)
the merode altarpiece depicts the annunciation, which in christianity, was when an angel was said to have appeared to the virgin mary to tell her that she would conceive and give birth to christ, the son of god. while this story was well known, the work contains a lot of obvious religious symbolism to further drive the point home.
i have labeled the middle pane of the triptych:
a. points to the rays of light represent god coming in through the window. this is right about the head of b, the angel delivering the news to mary. the fact that the line shines upon him gives mary and the view reason to trust the words of the messenger, as he is “illuminated.”
as we move onto the table, we see c. one of the books of the bible- this is either the old or new testament. i have guesses that would back up either. if it is the old testament, it would make sense that mary (f) would be reading the new testament as it is her story and more relevant to the specific moment. if the book (c) is the new testament, it is because the wind/light/god coming in through the window is changing that book (as the pages seem to be turning, the wind/god is moving the story along).
the next item on the table are d, the flowers. they are lilies, which represent purity, as mary is a virgin. the towel above them and the water that they are in represent this as well. the fact that the water is in a vessel can also be interpreted as pregnancy- mary is a “vessel” for the child.
the blown out candle, e, can be interpreted different ways. it may be representative of the holy ghost. it is also interpreted as the wax as “flesh” and the wick/flame as a “soul.” this could either be read as god (christ) springs from the human womb (mary), or that christ is flesh with a divine (flame) soul.
mary is usually represented by a star, and the light on her dress (g) is in the shape of a star. the fact that she is sitting on the footrest, and not on the bench, represents her humility.
Let's Get Visual Visual 
I love the way you make this so accessible to me, at least. I see how much thought goes into these pieces before they are created, so I guess I won’t have to delve this deeply when I’m analyzing pictures on Facebook!