When I think about visual musicality I think about the fact that we can understand writing and how to read it, we can understand music and how to listen to it, we can watch a movie and follow the action, we can look at an image such as in painting or a photograph and comprehend what we are seeing. These are all forms of communication that are secondary, which is to say, they are not primary events or actions from the natural environment or reality we live in. They are man-made and designed by humans for other humans to understand and enjoy.
We rarely think about it but there is a great deal more involved in designing these forms of art and communication than you might at first realize. A motion picture is a good example. We may not realize it, but it took quite a while for early film makers to figure out how to organize and edit a series of images in an order that a viewer could understand and that visually made sense. Then it took a while to figure out how to include sound and dialog and lighting to convey complex actions and establish the space in a film. It was not immediately obvious how to establish those conventions. It took a while to figure out how to design and it took a while to learn how to view a film and even now there are always new conventions, theories and experiments that film makers are trying out.
All forms of art are in a constant flux and state of evolution. Thoughtful artists are always questioning their mediums and challenging their viewers. Occasionally new, unexplored vistas open up.