This should be a fun exercise:
What in the world is this thing:
It's fair to assume that your knee-jerk response would be "a face." Okay, I'll go along with that, it's a face. Well, actually it's a picture of a face.
Or more accurately, a cluster of pixels that resemble a drawing of a face, encoded digitally and transmitted as electronic information from our server in Carlsbad, California.
Well, really, it's a signal processed in the occipital lobe of your brain, sent by the optic nerve which is reacting to light that . . . but never mind all that, we'll call it a face.
Now, what's this?
If this shape is half of a mustache...
...then is this really a necktie
decorated with a facial-hair motif?
Somehow, the identity of an image or object changes when the relationships between visual elements change. A bagel has a hole through it, but wouldn't it cease to be a bagel if that hole were filled with dough? Is the bagel defined by the dough or by the empty space?
A viewer sees a work of art as a whole that is more than the sum of its lines, or color, or size, or the space it occupies, or the materials used to construct it.
Taking notice of how the artist has chosen to orchestrate the various elements that compose a piece can lend insight into what the piece might be trying to suggest to a viewer, or why a piece of art evokes a particular response from you. A piece could suggest something as specific and figurative as a person's smiling face, or it could suggest something esoteric and subjective, such as the indescribable mood evoked by a painting that stands twenty feet tall in front of you, while not necessarily depicting a recognizable thing.