The picture on the left is of a humpback's head, but what isn't obvious -- or at least, it wasn't, for me -- is that it's really only the upper jaw. I had to Google images of humpbacks feeding in order to make sense of the various whale body parts I saw.
If you picture a giant toilet with the seat up, the upper jaw in the picture is just the seat. Underneath the water, the lower jaw is sitting there like an enormous bowl -- you can see part of the lower jaw in the picture on the right. That gives you a much better sense of the size of the creature who is basically just poking his nose above the surface.