What does this bark sound like? Alarm? A greeting bark? On a camping trip I bet its just plain old puppy silly excitement.
Islandog, I used to believe dogs can't see well, but Inga can see us give a hand signal from a quarter mile away
Your pup may have excellent vision, or, like my bear story, she knows or assumes you are you at that distance & sees the hand signal, your sillhouette, the familiar situation, the context, experience tells her its still you.
I can see well, but I still, briefly, mistook a bear for my husband. Brains are funny things. We have to run about assuming all sorts of things in advance, letting our subconscious mind assume friend or foe to free ourselves up to think.
I think if this pup is inexperienced and on high alert, the assumptions can move toward threat, and once that thought is fixed, at 8 months old, still learning, it's hard to get out of without confirmation.
All just guesses, of course.
The only thing I know for sure, is many dogs (not just my own) act suspicious in the wild.
(my current guy is the opposite, very relaxed on camping trips, like "dude, I looooove this")