Author: Greg Yau
Be in the position as shown in the first picture
Then, raise your upper right arm until it is just past parallel to the floor, with your elbow above the level of your torso, like in the second picture.
Pause, then lower to the starting position, and repeat (1).
After you've finished the reps on one side, switch to the other side.
Recommended tutorial: https://www.youtube.com/watch?v=ufhQhwyrx-4&feature=emb_logo
(1) The Men's Health Gym Bible by Myatt Murphy and Michael Mejia