The human eye is a funny thing. It likes to see visual space as much as it does objects.
Working in advertising I learned that white space – space free of text – is as important as the text. In fact it can either enhance or detract from the message. The same is true of graphics. Look at this photo.
It’s a lovely photo of sunset colors. But there is no focal point in it to demand your attention. It is suitable to set behind text, especially if it is used as what we formerly called an under burn, a pale format of the photo.
The second photo, however, has a focal point. Notice the silhouetted grasses at the front, providing perspective and leading your eye to the sun on the horizon. It’s a nice effect. However, inserting text might be problematic.
The third photo is totally reflective. The lines of the boat echo the lines of the clouds. Text in contrasting color could be added both top and bottom.
Graphics can enhance text or overwhelm it. Watch for balance when creating your design.