The description says that the Heart Nebula is shown on its side, which I'm sure is the traditional view, based on earlier, blurrier images. But I think it is right side up and almost anatomically correct!
As a veterinarian, I see the large cone shape of the ventricles below, the bulges of the two atria (plural of atrium) above, and even the major veins coming in from the right and left. The only thing missing is the aorta, which should be coming out of the top. However, the larger branch of the aorta curves back behind the heart, so its outline could be included in the bulges of the atria.
It's an anatomy lesson in space!