The focus of the video is explaining the processes Ninja Theory is implementing to create a grand world on a small budget. The video reveals that a single environment artist (of a team of only 13 people in all) is responsible for bringing the world to life. He's doing this by reusing assets for different parts of the world. In all, Ninja Theory says about 95 percent of the assets it creates for Hellblade will show up somewhere else in the game.
Nina Theory also writes in a PlayStation Blog post that Hellblade is still very early in development. What you see in the video only represents the tip of the iceberg for what the studio is aiming for with Hellblade, which--despite its small budget--is likely the studio's "most ambitious" game to date.
The studio added that for Hellblade, it announced the game so early in development because it wanted the game's entire development to be chronicled out in the open. "The standard approach is for games and their development to be hidden away, with details slowly drip fed to players very carefully and slowly over time. But we want to do the opposite," the studio said.