It's a good piece of architectural theory that actually applies to real world circumstances, which is rare.
Most people conflate the term "spacious" with a house that has many square feet. In most cases, that means a mansion with a shitload of unusable rooms clustered together. But there is very little that's actually useful about that degree of space if we can only occupy one room at a time in a house full of hermetic rooms that are generally redundancies of themselves. It's "exceptional" living only in a commercial sense, or a social sense related to the house as a status symbol of wealth. Most mansions are really dreadful pieces of architecture and are terrible places to occupy.
The opposite theory is that spaces are best when small and intimate, which is more typical of an urban environment for obvious reasons. This house is probably a more truthful medium. We need ample space for its own sake because it offers isolation and relaxation, but we don't actually need much of it for programmatic use, like cutting vegetables or taking baths, so the intimacy of rooms is beneficial too. Small is pragmatic. So this house has a large space for sensory pleasure and small spaces for utility. The low ceiling drop and the unusable area below it reduces any sense of claustrophobia or agitation that small enclosed rooms can create, without actually making the areas themselves cavernous or incongruent to domestic needs. It's quiet poetic.