They usually stand up on their hind legs to get a better look at things - I had a huge Alaskan brown bear do that about 15 yards from me on Admiralty Island. He then woofed twice and popped his jaw once - as I released the safety on my .338 the wind shifted and he decided to leave. I went back to camp and changed my underwear.
I can just hear the bear telling the same story from his POV to his friends. “He popped the safety on his .338 - as I woofed twice and slapped my jaws shut. The wind shifted and he decided to leave. I walked into the bushes and dropped a major load.”