t’s a mature cheetah however most predatory animals will react this way when their prey don’t take flight and face them to fight instead. An ostrich is very dangerous if it is in attack mode. Their claws could easily rip through that cheetah with one swipe and I think this cheetah didn’t want to take a chance.
Try to get your facts straight. Cheetah hunt both alone and in groups. It usually takes about 3 cheetah to take down one adult ostrich. It can be done occasionally with two, and it’s almost impossible with just one.