Spoiler alerts, obviously.
One of the few truly novel phenomena to stem from the rise of YouTube is the reaction-shot video. Ten years ago, the prospect of filming your buddy watching a twist in a movie or a TV show was a pretty dull one.
But. Get thirty people reacting to the same surprising event, and you've got something a little more infatuating. The 'oh shits' and drained faces and gasps grow more compelling as we encounter a veritable cascade of them. The best example of the genre, until now, was probably the reaction shot reels of the infamous '2 Girls 1 Cup' video, wherein folks who had already seen the disgusting orgy of skin and feces trained web cams on an unsuspecting friend (or grandmother or platoon of marines) who had not.
We relished seeing people in a moment of true candor, especially in this increasing era of nonstop self-cultivation. We relished seeing a pure, unrestrained rush of human emotion.
So. Last night, the concluding episode of Game of Thrones' third season featured a particularly shocking and brutal event. Readers of George R. R. Martin's books knew it was coming, so dozens of them trained their smart phone cameras on their friends and families while they were watching. One YouTuber then took the time to compile them all; the result is what you see above. Dozens of cries, yelps, shrieks of horror, some unflinching stoicism, and some genuine sorrow and sobbing. It's totally amusing and pretty compelling to watch, and for that, it climbed the front page of Reddit.
There are twin forces at work here—one is, sure, the availability of social-video sharing tools and the covert filming enabled by smart phones. The other is also a pretty unprecedented, if more mundane, factor: the death of a beloved TV character. Even in a medium as old as television, there are still relatively few examples of beloved or heroic characters dying unexpectedly. It just doesn't happen all that often. Sure, all those ER docs died off; but slowly, and sappily, after they've announced they're leaving the show and the writers had to find a way to speed their departure. That's how it usually goes on TV—the death comes with plenty of advance warning, in a fog of attendant press about the actor's offscreen ambitions.
Previously, maybe the most traumatic television death was M*A*S*H*'s Col. Blake—viewers were indeed already anticipating the departure of actor McLean Stevenson, as he'd previously announced he was leaving the show. But the writers set it up so audiences believed he was getting discharged; he died at the last minute, on his way home. If we had reaction shots of that, it'd be a more somber version of Robb Stark getting a blade through the gut. As with Blake, viewers know Robb's not coming back. Plenty of other TV characters have sort-of-died or died on shows that tease a return—big deaths on Dallas, Buffy the Vampire Slayer, etc don't hit as hard. Plus, people really love this Game of Thrones thing.
So you're seeing people react genuinely to the death of (another) character who stands for goodness and virtue in one of their favorite shows; yeah, it's amusing, but it's real. If you hadn't read the books, you had no idea this was coming.
Most of them didn't, anyway. This dude is totally faking:
But that's just another example of how far TV-watching and media consumption has evolved—the guy made a parody reaction shot video and uploaded it because he knew people like us would be watching.