Some strangeness, when I load the page directly from the local Raspberry Pi, it works. Always refreshes the latest images. But when I load the page from my web site, exactly the same files just FTPed moments after generation, it sticks with the old cached versions of the images.
So what, specifically is the difference between a regular refresh and a hard reload, looks like there's something to do with the server or how the files are copied over that might be the problem?