I quote from the YouTube page:
What is so special about this temple? This temple was not constructed by adding stone blocks, but an entire mountain was carved to create this temple. This is the only example in the whole world where a mountain was cut out from the top, to create a structure. In all the other temples and caves, even in Ellora and the rest of the world, the rock was cut from the front and carved as they went along. The whole world has followed a rock cutting technique called “cut-in monolith” while Kailasa temple is the only one that has used the exact opposite technique called “cut-out monolith”.
To see why this rock cutting technique is so different, let’s take a look at this pillar that is over 100 feet tall. See how small human beings look when compared to this pillar. Normally, to create such a huge pillar, it would take years of work, carving accurately on the huge rock. But this pillar was carved by scooping out all the pieces of mountain around it. You can imagine the amount of rock, which has been removed to create this pillar.