This is an interesting mount that can usually be accomplished without too much trouble. Starting on the spring board, the athlete jumps up and a little back, straddling the legs as much as possible and quickly placing the hands on the apparatus.
Still Frame 1 - Check at this point how the gymnast's weight support is on her arms with her shoulders in front.
Still Frame 2 - Notice the shoulders still in front at the skills completion.
Watch the whole skill at its regular speed.