Puppy pose is one of my FAVORITE stretches for shoulder and upper back flexibility. These 5 variations will help you deepen your shoulder flexibility for a bendier bridge/wheel pose. (Recommended to do these AFTER a warm up as part of a longer flexibility routine).
For a written pose breakdown, see my article, 5 Puppy Pose Variations for Open Shoulders (https://www.daniwinksflexibility.com/...)