I've seen this photo many times before, and I've always said, "cool photo of Draco contemplating life over a fire whiskey" or "nice Tom Felton jack Daniels ad" but now I'm like, "it's Erich Blunt! He's totally the killer."
In the movies, you can see the Hungarian Horntail Harry got is later seen breathing down fire at some chestnuts that children take out of the Weasleys Wizard Wheezes. So I'm guessing Harry gave his dragon to the twins. Maybe that is also supposed to hint at the fact that he gives them the price money to start ther business in the book which is never actually mentioned in the movies. But this is just a lil theory of mine.