This is a short Game of Thrones blooper reel released by HBO for San Diego Comic-Con. I'm not sure how I feel about it. On the one hand it was funny to see all the actors breaking character and having a laugh, but on the other hand...wait -- on my other hand it says, 'BUY TOILET PAPER'.
Keep going for the video.
Thanks to brand, Allyson, Linc and Whitish_Walker, who agree it's much more sad than funny when the actors on SNL break character and laugh at their own shitty jokes.