By strengthening her ability to be calm -- essentially "on command" -- we're dramatically decreasing the stress she feels around things over which she has no control. We begin by teaching her the Place command which requires her to stay on an object -- a door mat, a doggy bed -- until she's released. The first thing she perfects with the Place command is impulse control. Try it yourself... ask a friend to stay in one place and just see how long it takes him or her to go crazy with the need to move. The same thing happens to dogs. That impulse control serves them well in countless situations, again, not too differently from their human companions ;-).
Almost like magic, once a dog realizes that the rules of Place are rock solid (can't cross the border), he gives into it. He lies down, his breathing gets deeper and voila... he experiences what I like to call "doggy meditation". This is a pervasive, long lasting and long impactful change to a dog. So when you ask your trainer: Is my dog going to change from this training? Yes! ;-) Your dog is going to practice meditation on a daily basis and reap the same benefits that we all know humans reap from it, whether we're practitioners or not.
The day to day dividends are impressive. In Cassie's example, she went from a slightly neurotic basket case around skateboards and other dogs to a calm, relaxed pretty little thing that was interested in taking it all in but not threatened by the noise nor scent from either of those earlier threatening triggers. Bring practicality down to another level? She could go more places with her owner and everybody was happy with that!
Now, there's a disclaimer here that's important for all would be "Place Practitioners". The owner has to make sure that his relationship with his dog is good. He's got to practice leadership on a daily basis which is the underlying difference to a challenging dog's behavior. Doing Placework with your dog -- being insistent he follow your rules to a "T" -- is one of four impactful methods to establishing and maintaining leadership with him. Establishing leadership is harder. Chances are you're coming at this from a deficit. It takes a little more "proactive" effort and includes daily obedience exercises with your dog for a couple of weeks while he gets used to the notion of your being in charge. Maintaining leadership is easier -- no surprise ;-) -- and can be done simply by your being conscientous around thresholds, feeding, and elevation.
Lastly, take a hard look at what looks like a happy dog to you. Be sure you're not seeing nervous energy and confusing that for happy, go lucky excitement. Again, much like humans in this regard, dogs aren't really excited unless there's something to be really excited about. A balanced (psychologically healthy) dog enjoys relaxing -- do I need to say a lot like humans again? ;-) -- which might look like boredom. But relax... he's just meditating. ;-)