I think some breeds don't "display fear signs" and are
able to hide it better. They still are disturbed by whatever
it might be, but don't necessarily run away from it .

Most GSD's that I've known have an "interested" look,
rather than a typical fearful reaction to new things. Buddy
was fearful/but interested in the sweeper. I made a game
of running the sweeper & asked him to "come on" & help
me with the sweeping. He thought it was a game. I
never pointed it at him or chased him with it, but let him
know how much fun I thought it was to use. Later, after
I would put the sweeper away, Buddy would sometimes
pick up his tennis ball & bring it to the sweeper & drop in
front of the sweeper, like, o.k. "let's play". It's a game
he later played all of his life whenever I was busy & didn'nt
stop what I was doing to play with him. Dogs, you gotta
love um... I do.