Some of it is real (never underestimate the intelligence of a border collie!), but some is fake:
The creators of the video, for TV makers Samsung, revealed that they recruited Welsh national sheep herding champion Gerry Lewis, and a team of Welsh sheep herders to guide the flocks into position.
However they admitted computer trickery had been used.
Matt Smith, the co-founder of ad agency The Viral Factory said: "The people on camera are real farmers and they were really controlling the sheepdogs. Rather than trying to fake it all we did it for real.
"The sheep herding bit is straight up – no trickery but there is a fair amount of computer trickery and post production work.
"We thought the Mona Lisa was the big wink to people – once they saw that we thought they would realise it was not all real.
"But we have been quite surprised that there is still a debate about whether it is all real and people have been coming up with various theories."