After doing the last one, with the gods are spherical and planet-shaped, I figured I'd do a dumb, image-based joke. No theology.
Are the gods planet-sized? Not necessarily. You'll see them soon interacting with people, being about the size of their heads. Here, though, they're a little smaller than Mercury. They're gods: they're whatever size they wanna be.
Funny, of course, that they're talking about something named "Mercury," another god. Since the premise of this comic is that everything is translated into contemporary English, the planets get called what we call them.