Part-to-whole relationships and breaking those down into their functions is what we do when we analyze. We argue about how the parts function.
For practice, look at the following image.  It is Edward Hicks’s The Cornell Farm/.  The image has a fascinating composition, so watch the way one’s eyes are directed from area to area in the painting.  Are there any symbols?  Signs?  (Do you know the difference between a sign and a symbol?)

When we write, we analyze most of the time.  Whether we are reading a student post or model essay, we look over each text and think about how we are looking.  It’s a composition, so some of the vocabulary we use in its analysis is shared with other humanities courses like art appreciation or music appreciation.

Consider how the whole is broken down.  If its artful, then there’s a guiding of one’s eyes as well as a frustration of easy expectations.  See what you see and share that!  Again, italicize the artworks’ titles.

Edward Hicks, The Cornell Farm (1848).

Clearly, we can argue the parts and how they function.  Analysis is all about functions in the structure and effects upon the viewer/reader.  It’s worth remembering that the act is destructive (lysis meaning just that), sort of like taking apart a watch and seeing if it will function without this or that gear.  And, no, don’t use the creationist blind watchmaker argument here just because I mentioned watches.  Their idea that something as sophisticated as an eye could not have evolved is easily-enough refuted.