Nope, it's not Down Dog, but Dolphin Pose is a heck of a pose!
There's no doubt that Dolphin looks very much like Downward Facing Dog. However, Dolphin would be considered by most yogis to be a bit more difficult. It's safe to say that most students wouldn't consider this posture to be a resting pose. Chances are you will be surprised by the physical challenge of Dolphin Pose. The major difference between the poses is that Dolphin is practiced on the forearms.
This pose is commonly used as a preparation posture for more challenging inversions. Dolphin is great for building strength in the shoulders, arms and upper back, this allows a yogi to get better prepared for postures like Forearm Stand. Some students may also prefer Dolphin as opposed to Down Dog since it protects the wrists from strain.
Ardha Pincha Mayurasana is the Sanskrit name for this posture. The breakdown for the Sanskrit name is as follows, "Ardha" meaning "Half", "Pincha" meaning "Feathers", "Mayura" meaning "Peacock" and "Asana" meaning "Pose". Forearm Stand is called Pincha Mayurasana, so Dolphin could be called "Half of a Forearm Stand" as it resembles Forearm Stand before lifting off the ground. You may come across some yogis who have been trained to refer to this pose as Puppy Pose.
If you're ready for an awesome intermediate level pose with plenty of benefits and challenges, then Dolphin Pose awaits.