We've seen an Xbox One playing through another Xbox One. And an Xbox 360 through an Xbox One through an Xbox One. Also a Wii U through an Xbox One and, sure, a PS4 through an Xbox One. But what if you plug one Xbox One into itself? Because it's certainly possible. And the results are kind of beautiful.
It's kind of like pointing two mirrors at each other. Interactive video game mirrors, that is.
That odd, alien sound you hear is the infinite loop of shifting menus, which would normally make one quick burst of noise were it not plugged into a looping image of itself.
Here's what's happening here: the Xbox One has an HDMI input that allows you to plug and therefore route a cable box and other HDMI devices into it. From there, you can use the Xbox One's "snap" features to get to the Xbox One Guide or to watch TV in a sidebar while playing a game. You can theoretically plug in any HDMI device, even a Playstation 4.
What we did above was split the HDMI signal so that we could send the same video signal to the TV while looping it back into the very same Xbox One it was coming from at the same time. The result is what you see above.
Useful? No. Oddly pretty to look at though.