The basic feature of fetching latest image is now available on Illinois LSST server. It will automatically try to fetch and display a new image file from another visualization/image server (which currently also runs on the same server machine). It might need few seconds to update. User can also pause or resume by the button.
The visualization-server from @tony_johnson right now always returns an empty FITS file. So Firefly is probably displaying a default one and we won’t see any change in the latest image. We will need to test the performance once the server can return URIs of real images.