A lot of my work is invention. I like to remind people, clients, that inventing metaphors is something a photographer can't easily do.
What is the idea about? What is it like? What does it resemble? By reducing something to its basic "thingness" you can manipulate it more easily to resemble something else. This globe became a tree. Breaking off the top of the tree like the top of an egg revealed what? Maybe it's a birdbath, then. Maybe this is about the finite nature of water.
Visual metaphors don't need to be concrete, in fact they work better if the description is vague. Better still if the drawing is somewhat awkward and blunt. The less perfect it is as itself the more the eye looks for what it might be, if there might be a hidden meaning. Absolute photographic realism doesn't suggest as much.