Barbs are a huge family. They come with all shapes, sizes and needs. With tiger barbs, I see that tank as a really nasty environment. The sand cascading around is cool, but tiger barbs, well cared for, can beat 3 inches easily, and are heavy bodied.
Like a lot of aquascaping videos, that one isn't designed to last. Put the fish in, film it and then scrap the fish is a common approach online, sadly. The fish don't live long enough to worry about. A lot of the fantastic scape tanks I've seen have had 3 week lifespans.