Yes, that is a seal riding on a humpback whale's back! [Photo Credit: Robyn Malcolm/Diimex.com.]
This is THE BEST! "When a pod of whales tucked into a feeding frenzy on the [New South Wales, Australia] south coast there was plenty on the menu—even enough for a surprise guest. Amid the pod of humpback whales in waters out of Eden, an opportunistic fur seal wasted no time in finding the best seat for the fish feast. The odd pairing was captured by photographer Robyn Malcolm on a recent whale watching trip out of Eden. 'We'd seen some amazing whales coming out of the water, everything was happening so quickly. And it was when I went back through the photos that I realised I had actually captured the seal on top of the whale.'"
In the video at the link, an interviewer asks Malcolm how people can be sure she didn't photoshop the remarkable image, to which Malcolm responds: "I don't know how to use photoshop! And I do still have it on the camera, so I can prove it." Haha!