It's not about some specific design, it's about GoodSpace.
GoodSpace in a design accommodates well the forces anticipated for it. That means ample, well-labelled locations exist for whatever we expect to achieve in the space for a long time to come.
For our purposes, then, ample space means adaptable space. The creator of a good space was foresightful and recognized areas where needs would change. When an outside observer focuses on the space for the first time, with a specific change in mind, they are likely to know where to get to work.
An analogy can be drawn to a chess player who knows when they have a good position on the board. The player sees the locations in which their strategy could "hinge", "flex", or "change" according to the environment on the rest of the board.
Many design patterns evolve from good old fashioned space management.
The term GoodSpace is about as ambiguous as it gets! But, I think good and space get defined contextually here. Essentially, we suggest design principles commonly emerge from specific foresight about where one ought to leave RoomToGrow?.
Just don't let PeterMerel get hold of this ... especially if it gets renamed VeryGoodSpace?.
You may find additional useful information about writing the right layers into your programs at SubjectOrientedProgramming