Part of the promise of USB Type-C is the ability to connect non-USB signals using the same cable. One such specification is DisplayPort, the kind of cable you use to connect to certain video monitors. It turns out, if you connect an LG G5 to LG's 4K 27UD88-W monitor using the provided USB Type-C to Type-C cable, you can mirror your display.
And if you play a video from certain apps, the content will show up only on the larger screen.
GTrusted shows the magic in action. The reviewer noted that the connection only worked with the cable that came with LG's monitor. Trying to use another cable such as Apple's didn't work. LG warns that you should only use its cables whenever you plug in someone else's.
It's impressive to see this functionality supported, especially since LG is using not-yet-Benson-approved cables. But it's not exactly favorable for consumers to be limited to buying more LG-only gear.
Still, to make the situation sweeter, that monitor will also charge your G5 while the phone is connected. If you want to buy one, you can find it on Amazon for several hundred bucks.