Troll, yeah, the bear's action is called a bluff charge, and that's typically what it is with bears. You'd want to puff up, be loud but low toned, raise your hands out and over your head, and if you don't have a gun, you'll want a club, spear, or arrow to either hit or jab the nose. Bears are like dogs, their main sense is the nose, they see with it, so damaging that vital and tender portion of the body is your best chance in an actual attack. To illustrate how important it is to make yourself appear larger, and especially taller than the other animal consider our llama. He is an aggressive male and he tries to assert his dominance on most people who visit our farm by rearing up, which is extremely dangerous because his forked hooves are like blades, and he could seriously cut you open of he put some muscle in to swatting you with them. When I first came to the farm here he would treat me the same way. I would always have to keep one hand above my head to appear taller, and in that case he would leave me completely alone. Now I use my body language and snarls to convince him to keep his distance so I can use both my hands for my duties. But anyone who raises their hand over their head, and is taller than him, can easily keep him back, whereas if you keep your hands at your side he will get dominant with you.
AltBeast, the first video is of a man confronting a couple male lions on foot. His means of being close is interesting, because he's laying down part of the time, but when the lions get to close he pulls out a roll of toilet paper which apparently backs them off. In this case the white of the toilet paper would catch a lot of light and appear as if he's waving something glowing at them. But the take away is to have the proper energy. The man is mere feet from these male lions but does not back down and projects dominance and assertion.
With the bear, a man and a filmer are picking berries in the woods when he is confronted by a grizzly, she charges him a couple times, and he stands his ground, or advances a step and she backs off and turns heal.
Body language is absolutely huge in the animal world. It can be the difference between an attack or not. Or between having birds (or squirrels, or chipmunks, etc) tell everyone in the area that you are on the hunt.
Learning to be aware of and control your energy is paramount to being a native in the woods, instead of an alien.
