It was halftime of Game 5 of the Finals. The Spurs were up, ABC cut to commercial, and everyone got ready to zone out or grab a snack or hit the bathroom or whatever, and then BOOM: nine-hour long Samsung/Jay-Z ad. It damn near broke the internet. (Incidentally, note the prominent Brooklyn Nets hat even though Jay-Z is a fan/agent now, not a part owner.)
Here, from The Verge, is a lot more background on what that all was.