There is only one descriptionof the physical appearance of Jesus given in the New Testament, and the depiction of Jesus in pictorial form was controversial in the early Church. The depiction of him in art took several centuries to reach a conventional standardized form for his physical appearance, which has subsequently remained largely stable since that time. Most images of Jesus have in common a number of traits which are now almost universally associated with Jesus, although variants are seen.
The conventional image of a fully bearded Jesus with long hair emerged around AD 300, but did not become established until the 6th century in Eastern Christianity, and much later in the West. It has always had the advantage of being easily recognizable, and distinguishing Jesus from other figures shown around him, which the use of a cruciform halo also achieves. Earlier images were much more varied.
From the Daily Beast:
What do you imagine when you picture Jesus? Do you picture a fair-skinned man with flowing light brown hair in a white caftan? Do you try to be more historically accurate and imagine him as a Middle Eastern man with tanned or dark skin, dark hair, brown eyes, and perhaps a beard? Or do you envision a balding man with a monobrow, hunchback, and patchy beard who stood about four and a half feet tall? If you picked the last option then, congratulations, your perspective aligns with that of the early church.
Though scholar Joan Taylor has written an excellent book on the subject, we do not know what Jesus actually looked like. The Bible tells us absolutely nothing about Jesus’s facial features. The only real interaction with or discussion of his body comes after he is resurrected from the dead when the Apostle Thomas says that he wants to put his hand on the marks of the crucifixion. And that’s it. We don’t know how tall he was, if his nose was crooked, what his hair was like, or if he had smooth skin. We know a little bit about his fashion sense—he advises against wearing flowing robes in Mark 12—and his face shone brighter than the sun during the transfiguration. But there’s nothing that would lead you to swipe left or right on his profile.
Exodus 20:4–6 “Thou shalt not make unto thee any graven image” is one of the Ten Commandments and except for minor exceptions made Jewish depictions of first-century individuals a scarcity. But attitudes towards the interpretation of this Commandment changed through the centuries, in that while first-century rabbis in Judea objected violently to the depiction of human figures and placement of statues in Temples, third-century Babylonian Jews had different views; and while no figural art from first-century Roman Judea exists, the art on the Dura synagogue walls developed with no objection from the Rabbis early in the third century.
The earliest surviving Christian art comes from the late 2nd to early 4th centuries on the walls of tombs belonging, most likely, to wealthy Christians in the catacombs of Rome, although from literary evidence there may well have been panel icons which, like almost all classical painting, have disappeared.