How to force refresh upon page load?

Working using Responsive child theme.

I have an image called chameleon.png, imported as media, and posted into my Home Page under Appearance->Theme Options.

When importing a new look of the image, I always delete the old image, then upload the new one, and then put this in the Home Page post area (Add Media)

Clicking ‘Visit Your Site’ at the top, my new page loads, and the old image remains, but when I refresh, it shows the new image.

I don’t want people to have to refresh, as most visitors will not.
How can I bypass this problem, have looked into AJAX but it’s a little unnecessary given that it’s a simple forced refresh (though it doesn’t seem so simple looking around).

Much thanks ahead of time.