Actual size: 1.4 inches across! Look at that detail in that size. Wow. The sculptor really had mastered human anatomy. I didn’t think anybody had mastered the human body like that until Leonardo da Vinci 2,000 years later.
There are Roman coins that are less than 1/4” in diameter with complete inscriptions. Now of course the dies were made, in reverse. If there is a mistake, you know it is barbaric copy, the Romans believed in quality control. The moneyers either had phenomenal eyesight, or they a way to magnify what they were looking at.
The early anatomy and perspective were excellent. It was a conscious desire to replace perspective and anatomical detail with Christian symbolism that changed art drastically. And that lasted for centuries until they “rediscovered” perspective. That’s not putting down Christianity. That’s just observing how it affected art styles. (Very old U of Chicago Art History major)