As I work with Kody on improving door greetings, this brings up a sort of uncomfortable situation. You have to train your friends. I pay close attention to Kody to watch his body language and can usually tell what he's thinking or feeling. But dogs are very subtle and it's taken me a log time to be even half way decent at this and I still have much more to learn.
Likewise, when we're working on greetings, I also watch my friends very closely. The friends all have their own issues I have to work with. One wants nothing more than to just give Kody a great big hug and lay down on the floor a let Kody lick his face. Of course, this would make Kody pee almost instantly. So I've explained to him that his presence is the greatest gift to Kody and he shouldn't look at or talk to him because the scents on him are enough to keep Kody's mind fully occupied.
This friend is as bad as Kody. He just can't control himself, he lets little exciting signals to Kody slip out. He'll speak in an excited voice. Despite my instructions, instead of just glancing at Kody, he'll look at Kody and get locked in a stare, which is very intimidating to a dog. Then I've got this situation where Kody and my friend are locked in this crazy stare and I have to say, "Stop looking at Kody!" And my friend seems to have to gather all his strength to break the stare and then I can tell he's still magnetically drawn to stare again. I have to watch him like a hawk, although now he's getting better about realizing he does this and stopping himself. He's as hard as the dog to train!
In my friend's defense, this sort of human behavior is common. Most dogs that owners take out into the public are there because they're greet humans well. Because of that, that's how most humans think all dogs behave. Humans really have no idea how to interact with dogs. What's worse is they don't trust a dog's owner knows what they're talking about. Lets face it, most of us don't know, but whether you agree or disagree, you have to defer to the dog owner's direction. Even if they don't know what they're doing, they may know when their dog is about to bite you.
When we're out on a walk people want so badly to bend down. Somehow we all got this idea that for a dog to "get to know you" he has to smell your hand. That's not true! A dog can smell your legs and be fine, your hand doesn't have to get near a dog's mouth for him to smell you. In fact the dog probably wants to smell your shoes more because those have all the fascinating stuff you've picked up from other places.
It's an interesting road. It takes every bit of my last two years of experience to be able to begin to handle these situations. It really doesn't help that it's considered rude to tell another person not to look at something or how to adjust their body. Training humans is a difficult skill to develop.