Yeah it has been there before. It used to be a Hunter minion (I think), but was then removed from the game and not used. Could be that they use the art again with the upcoming expansion, but it is old art for sure and it has been on the page before.
That's true, but I recall there were Gadgetzan pictures there before, like that second leper gnome. It can't be a coincidence THIS pictures of all was put there, when there is already some "evidence" of dino land area to be next expansion.
I could be wrong about this since I don't check hearthstone home page often but, I'm pretty sure this picture was NOT there before.
It's on the very bottom with other pictures.