Feature suggestion: thumbnail for background image in header elements

I'm not quite sure whether this is far too specific. I use header elements a lot. It's a great and versatile feature. Since full-width header images are nowadays pretty much the standard layout, many users do probably use this feature. One minor issue is that you can't easily see which image is shown by which element. This might not be a problem with 1 or 2 elements. With 10 or more header elements, however, it would be a great help to have a thumbnail in the overview table (similar Woocommerce products, for example).

Thanks, Mike