This is great because it forces participants to carefully consider the _details_ of each others' designs.
As a designer moves along he or she will invariably encounter lots of little constraints that were previously unknown. A good design is a response to all of these details. As a reviewer its all too easy to dismiss a design: "you should have just done X". But the designer will respond "it was considered but I found extra requirements Y and Z that preclude X."
Communicating these details is difficult. You may not always remember all of the constraints you've discovered. A process like the one posted should help to get everyone thinking about the details discovered by each individual.
As a designer moves along he or she will invariably encounter lots of little constraints that were previously unknown. A good design is a response to all of these details. As a reviewer its all too easy to dismiss a design: "you should have just done X". But the designer will respond "it was considered but I found extra requirements Y and Z that preclude X."
Communicating these details is difficult. You may not always remember all of the constraints you've discovered. A process like the one posted should help to get everyone thinking about the details discovered by each individual.