A good way to capitalize on this focal space is to add a fun collage of empty frames. You can see on the picture above how easy it is to create one. All you need is frames. They can all be the same color for a sharper appearance, as pictured above.
Another idea is to focus on the contrast in the shape, color and style of the frames. Or you can add a different color frame for the contrast. To add color, an image might even contain some art. You can then overlap them, which would create a bold geometry in the space.