The dog was just saying hello. The owner should have their dog under control, though.
A few years ago, I was in the forest with my puppy and an elderly friend. A huge Akita came running up to us, jumped up with his paws on my shoulders and stared at me.
It seemed expressionless to me - so I had no idea if it was friendly or hostile. I averted my eyes, stood still and froze.
Eventually, a man came running up and said 'It's OK, he's friendly, still only a puppy!'
We didn't know that, did we?
I was shaken, my friend was terrified, no knowing what to do. Always it's the idiot owner at fault - not the dog.