I wouldn't use this video as a way to test or evaluate this puppy at all. His behavior in this environment did not look totally relaxed, nor did it look totally stressed. In order to have any opinion on this video at all I would at least need to know if this was his first time ever out into the public, or has he been exposed to this type of environment his whole life? If this was his very first time out in the public then I'd say the way he handled it was acceptable. If he has been exposed to this sort of thing many times, and for example this was 6 hours into his third day at this expo / event then I'd say he is a little more worried than he should be. This opinion is only assuming its the environment that the dog is worried / conserned about. If the stress is coming from his handler then that is a whole different issue all together.
So in short, we can tell nothing at all about this video other than its a black pup walking through a crowd of people inside a building.
If this were my pup I'd be trying to free him up more, bring him up a little in drive and make this a happy expierence for him. Why would I want to put presure on him here so that he can make a negative association with this type of environment at a young age.