This page is designed to automatically test if the browser supports HDR and then automatically render the best version of the image for the display. You may click th the green button (bottom left) to override the default and compare (to see how an HDR image tone maps on an SDR display, or how much benefit the HDR image offers on an HDR display). View this page on the Canary or Dev builds of Chrome for best results (they have updates for more accurate rendering of properly encoded HDR AVIF images which should eventually make their way to an official release).