Bitcoin is a peer-to-peer electronic currency, just like Satoshi said. When people start calling it something else, like "a swarm of digital hornets", "digital gold", "art", "revolution" and so on, it suggests that it isn't doing well as currency, because otherwise people wouldn't need to create new narratives of what Bitcoin is.
As for art, wikipedia defines it as:
Art is a diverse range of human activity, and resulting product, that involves creative or imaginative talent expressive of technical proficiency, beauty, emotional power, or conceptual ideas.
And Bitcoin is neither of those things, it's simply a tool for storing and transferring value online.
Bitcoin is a peer to peer electronic cash system that works perfectly as a currency. No Narratives needed for it to be a currency nor an art piece.
Although this definition runs short as what art is: "creative or imaginative talent expressive of technical proficiency, beauty, emotional power, or conceptual ideas." Bitcoin is a minimalist code which is speech. A Creative speech. a technically proficient code. A beautiful code for a currency. A code So powerfully filled with conceptual ideas, that evokes all sort of emotions.
Bitcoin is Art because some perceive it just as a digital currency. Some others as a store of value. Bitcoin is art because those who are against it because of their own fears, subjectively perceive it as a ponzi, and when their paranoia exceeds rationality, they even feel Bitcoin as a weapon. this is why Bitcoin is art.