An explanation of the name choice from Square's tweets:
> Not to get all meta on you… but we’re going to! Block references the neighborhood blocks where we find our sellers, a blockchain, block parties full of music, obstacles to overcome, a section of code, building blocks, and of course, tungsten cubes.
> Not to get all meta on you… but we’re going to! Block references the neighborhood blocks where we find our sellers, a blockchain, block parties full of music, obstacles to overcome, a section of code, building blocks, and of course, tungsten cubes.
https://twitter.com/Square/status/1466158911413760004