The viewer of a photograph lives in a society, generally. That society has ideals, values, politics, and history, and by living in it the viewer is thoroughly steeped in these ideals, values, politics and history. We all, viewers of photographs and otherwise, have our heads full of visual symbols, of shorthand representations of ideas and themes, which have been impressed upon us by our society, in our schools, museums, and by our media.
A person looking at your photograph has seen other photographs, quite possibly a lot of other photographs. They have seen movies, they have watched television. While the viewer may not know it, he or she is in some ways deeply familiar with the local dialects of visual language.
The viewer too has specific ideas, dreams, ideals, values, and history. We all experience new things in terms of things we have experienced before, through the lens of our own history. We see a photograph, and we compare it to similar scenes from our past, we compare the people in it to people we have met.
A liquor bottle in a photograph reminds us of drinks we have drunk, of alcoholic relatives, of parties gone good or bad. It reminds us of ads for liquor we have seen, and the feelings those ads evoked. We associate it with social mores, good or bad. We might well remember some snobbish discussion about phallic shapes, re-triggering that sexual association. There are layers of semiotics that will cascade into our minds when we see almost any identifiable object, or even if we think we can identify an object. What would a photograph of a flower do? Of a nude man?
Now place that photograph next to some explanatory text, or with a group of other photographs. Display this somewhere. The things surrounding the photograph now generate more mental activity.
Somehow, the viewer chews all this stuff up and, if paying attention, arrives at some simple conclusion, usually "I like this" or "I don't like this".
If little or none of this stuff happens, either your photograph or your viewer is an abject failure. If the viewer does not experience much of this, your photograph probably failed to capture their eye for any length of time, and certainly failed to engage their brain.