The "just breathe" of zazen's meditation asks you to not to think on that that is in your mind; either could being the solution of a code failure, the final strokes of a piece of art, or the imagination of doing a kick-flip on a skateboard.

This is pretty hard to achieve. First it'd be easier to shut the environment stimulus, the noises and distractions. Probably later the worries and anxieties; thus the "keep focusing on breathing" becomes the hook, or attachment to not get lose, for saying it some way.

What is the point? As with epoché, the "shutting down, or bracketing" of things may be a way to reach eurekas, however that isn't the main goal of zazen but possibly a side yield. With zazen, I think the importance is to gain memory that this world isn't the only thing that it is, in other words, zazen is not to "bring" this or that to this world, and as with Vegas, what happens in zazen, stays zazen.