<span> The most obvious answer is that the artist was either commissioned by the religion and thus produced the images that his employer wanted to see or he sold his art to religious people and thus had to produce the images that they wanted to buy so there is the marketing aspect to it all
I mean look of the most popular image of Jesus;the Jew is long gone and he looks like John Lennon circa 1967 [w/o the glasses of course] then look at some of the Renaissance images of Jesus which show a much darker man with clearly Mediterranean features
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The animals are more realistically drawn than the humans.
