The human figures in the images are 5'9" tall.
A weird notion occurred to me while generating these images. It began to look as if the elevation of the Arch of Constantine matched the interior elevation of the Pantheon, as if the Arch of Constantine were like the Pantheon inside-out. I quickly checked to see what the interior of the Pantheon actually looks like, and, alas, the two elevations are different in several significant ways. Still, I might just 'construct' a model of the Pantheon interior using the Arch of Constantine as my guide.