The Machines never show up on the page, but they're the center of attention in this story. And it's too bad that they're the center of attention because they seem really boring. That is, after eight stories about how complex and loving robots can be—from Robbie, the caring nursemaid, to Stephen Byerley (maybe)—we end up with robots who are so specialized that they lack personality (Evitable Conflict.53). This is especially confusing since we saw how Brain was useful in "Escape!" precisely because he was a robot with a personality.
Although maybe that's part of the point of these robots—they may be the most inhuman of any robot we've seen, but they're also some of the most necessary. That is, they don't have much personality—they're just calculating machines. But they're the ones who keep the economy moving and make sure that conflicts are avoidable. In a way, they're like an improved version of Herbie. Herbie had an expanded version of the First Law that included hurt feelings, but he wasn't taking the long view; by contrast, the Machines are taking the long view and also have an expanded version of the First Law, since they are considering all of humanity.
What does this robot tell us about robots? While still keeping to the Three Laws, the Machines may be manipulating issues without human consent. Whether this is a dangerous thing or a good thing depends on your point of view.