I am interpreting it as an n-dimensional graph (let's say 2D for simplicity), and the axes may be something like "speed" and "scale", or "cost" and "risk", or whatever your parameters happen to be. The solution is somewhere in the space defined by those axes, but you don't know where it is yet, and you don't want to lock yourself in to a single point too early. The axes themselves could be anything. You are choosing what to care about. Ideally, it should be informed by understanding your users, your stakeholders, your domain, your market, resources, available technology, divine inspiration, etc., but it's an important decision that is probably completely contextual and is part of the design process.
I could be wrong, this is, as noted, just an interpretation.
I could be wrong, this is, as noted, just an interpretation.