Most likely the jump is using a timeline to animate how long it takes to hit the ground after you either run out of your updraft, and or you let go of the key used to trigger it. And the movement of the crosshair is just using a simple camera shake. However, there are multiple ways to create a first person camera. Some attach it to the head, and turn off collision. Others just have arms. I’m assuming from the player’s perspective they just use the arms, but from other players they are using character models. I’m not too sure of that.