There's a HDR video on that page, and on my built-in MBP display, it's much brighter/has noticeably more range than the rest of the UI. Moving the window to my

There's a HDR video on that page, and on my built-in MBP display, it's much brighter/has noticeably more range than the rest of the UI. Moving the window to my non-HDR external 4k monitor, it looks like a regular YouTube video. The video looks the same in both Safari and Firefox, whereas the images are dim in Firefox on both my MBP display and external monitor.