I recently read a statement attributed to Miles Davis (possibly the greatest jazz trumpet player of all times - but that's for another time), that he played not what was there, but what was not there.
As I have thought about my own visual development, I have come to the conclusion that I prefer images that leave something to the individual viewer's imagination. Some images are too easy. After the first time you look at them there is nothing left to discover. What is not shown may be more important than what is shown. It leaves room for individual interpretation and discovery.
I understand that making such an image is easier said than done. We are often attracted to a subject because of the interest that it holds for us. We see it. We feel it. We sort of have a relationship with it. It is not easy to see what is not there because we are so aware of what is there.
However, one of the necessary skills for photographers is editing. We may take thousands of images of what and where we point out cameras, but then we should edit heavily. There may seem to be very little difference between one image and another, yet one has life and speaks to us while the other doesn't. This is where visual literacy comes into play. It's having that sense of what makes one image work and another not work.
Visual literacy is difficult to teach and probably takes years to acquire. We are very good at teaching people how to change an image but not very good at teaching them why and what should be changed to make an image come alive. Visual literacy is acquired by looking at a lot of work and deciding for oneself why an image is great or merely near great. Where that line is drawn is a personal decision. Where I draw the line is not necessarily where someone else would draw it. It's the result of how we view the world, our exposure to visual images, and our own personal life experiences. It can be acquired but it takes some work and the self awareness to realize that it needs development and nourishment.