Extended Puppy Pose is like a morphing of Downward Facing Dog and Child’s Pose. Its a wonderful shoulder opener with lots of variations. Here are 4 that I find really helpful.
Normal Uttana Shishosana has arms extended out in front, chest relaxed down towards the mat, and chin or forehead resting on the mat and your hips above knees.
For a more intense sensation try resting your elbows on blocks in front of you and allow your head to relax down.
For less low back pressure try resting your elbows on a chair or your inversion trainer.
If you want to get some inner thigh stretch and the shoulders try your puppy with a leg extension.