I am certainly not saying that I am always successful in doing that nor to I have the magic formula that yields that result every time. Since I dabble in geometric abstraction and Surrealism in my drawings and paintings I try to bring some of that into my photography. I think that the short answer is that even if the image presents something that is representational, which allows the viewer a point of access, I try to include something that provides a bit of mystery or give them a reward for lingering on the images a bit. If the subject is abstracted, perhaps they will ask themselves what the image is before going on to understand what the image is about. Or, for someone who may be attuned to photography, they might be intrigued with “how did he do that?”
I have some recent work on display at the university where I am finishing up my BFA and one of the administration people called me out from the drawing studio to ask me questions about some of the pieces. In one of them, which was representational but heavy in the juxtaposition it of images, she was trying to understand what it was and asked if she could touch part of it. It was the portion of the drawing where I’d first printed a cyanotype made by sandwiching a positive and a negative to provide a bas-relief effect. I agreed and after she felt that it wasn’t actually engraved she thought more about what the image was about and had some interesting comments about it, transitioning from “what am I seeing” to what is this really about and understanding why she struggled getting there at first.
BTW, I highly recommend a podcast called The Lonely Palette. It’s a short look at works of art, led by an art historian. It is not as dry as you might think. It focuses on a specific piece of work from the art museum in Boston and each episodes starts with a recording of random viewers in the museum describing the work: what they see and what is means, to them.
http://www.thelonelypalette.com/
One thing I’ve learned through the BFA process is the value of critiques. Every assignment culminates in a class critique where they try to sort of what the work says based on what they see and, sometimes, how well this aligns with the artist statement.
So, to answer your question, I think that an important part of the formula is to get LOTS of feedback on your work. Lots.