Connecting Images
The best way to figure out what the Messiah looked like was by reading the bible. A lot of historical painters failed to find helpful details in the holy book, however. This was why these painters worked on the image of Jesus Christ based on their own model. However, they also relied on the works of older artists when they came up with their own version.
An Improved Image And Feature
Artists were able to make a new version of the Savior. They used features from the older works, which explains why they are different but still similar. Back then, the artists wanted to create an ideal image of the Messiah. When they worked on their projects, they often based the appearance of Jesus Christ on earlier works of art of Him. This explains why this depiction has become so prevalent.