The phrase "concrete image" is correct and can be used in written English.
You can use it when you want to refer to something that can be seen or experienced in a tangible way, rather than something abstract or conceptual. For example, "The author's writing created a vivid, concrete image of the setting in my mind."
He starts with a concrete image and gradually transforms it into something fantastical and absurd but slyly believable.
I had no concrete image of what I wanted to write about — just the conviction that I could come up with something that I'd find convincing.
But Moses rightly worries that Aron is too sympathetic to the craving of the Israelites for a concrete image of a god.
Whereas metonymy typically provides a genuine image for an abstraction, synecdoche is a descriptive literary term that uses part of an already concrete image to refer to said image for rhetorical purposes, such as to highlight a specific feature.
Then she tells them to review the problem for a few minutes before going to bed, and once in bed, visualize the problem as a concrete image, if possible.
There is definitely some overlap between the two concepts, but, put the simplest way, synecdoche typically refers to an already concrete image used for purely poetic and rhetorical purposes.
They mostly used abstract figures or concrete images (faces and flowers) deconstructed or magnified into abstractions.
It badly needs the concrete images, the real people that will anchor it to reality.
There were no concrete images of the clinic itself, no pictures of whatever this boiling machine might look like.
Although not programmatic works per se, Leos Janacek's two string quartets rely on concrete images to convey meaning.
"He might be saying metaphorical things, but he uses concrete images which are easier for Western people to appreciate.
