html
<meta http-equiv="Accept-CH" content="DPR, Viewport-Width, Width">
...
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        /image/thing-crop-1600.webp 1600w, /image/thing-crop-2000.webp 2000w"
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    <!-- serve JPEGXR to Edge -->
    <source
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    srcset="/image/thing-200.jpgxr 200w, /image/thing-400.jpgxr 400w,
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        /image/thing-crop-1600.jpgxr 1600w, /image/thing-crop-2000.jpgxr 2000w"
    type="image/vnd.ms-photo">
    <!-- serve JPEG to others -->
    <source
    media="(min-width: 50em)"
    sizes="50vw"
    srcset="/image/thing-200.jpg 200w, /image/thing-400.jpg 400w,
        /image/thing-800.jpg 800w, /image/thing-1200.jpg 1200w,
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