The phrase "a visual explanation" is correct and usable in written English.
You can use it when describing an explanation that is conveyed through visual means, such as images, diagrams, or videos.
Example: "The teacher provided a visual explanation of the concept using a detailed infographic that illustrated the key points."
Alternatives: "a graphical explanation" or "a pictorial explanation".
The technology provided a visual explanation of how James used science, engineering and architectural techniques.
To peruse: A visual explanation of the Curiosity rover's position on Mars.
Science@NASA has produced a video, called "Rock Comet Meteor Shower," that provides a visual explanation of Thursday's Geminid meteor shower.
Spectators who have not connected that name with the pioneering racetrack surface of Indy's past need only look as far as a strip of red blocks at the start-finish line for a visual explanation.
The purpose of this paper is to give a visual explanation of the mechanism conducive to roll lock-in and catastrophic yaw and relieving means by answering the three questions: Why does the wobbling motion appear?, What is it that makes the wobbling grow to very large amplitudes?
Creating a visual explanation is an excellent way to learn and master complex systems.
A diagram on the car park wall offers a more visual explanation.
Below, images of Solaris in action, followed by a brief visual explanation of how the apparatus works, and an extended cut of the project demonstration shown above.
For a more visual explanation of the servers involved in MIT's mail filtering, reference Jacob's powerpoint.
If you look at the upper right corner of the new design, you'll see a simple, visual explanation of the strongest and worst of your personal portfolio performers.
When we first meet people in this world, we see a brief visual explanation of how they killed themselves, and every glimpse of the world of the living is a brightly colored contrast to the drab, washed out panoramas of the afterlife.
