How come in pictures or artwork, when they do couples or friends they're never of different race?

Often art imitates life...How come in pictures or artwork, when they do couples or friends they're never of different race?
I walked into a shoe store today and saw a photograph/advertisement of a IR couple with a White baby.





It was funny...





It was a Christmas setting, fire lit fireplace, the little girl with a bow in her hair, smiling, with a present in her hand.





blahHow come in pictures or artwork, when they do couples or friends they're never of different race?
That's not truee. I've seen pictures and artwork of couples and friends of different races.
Because in art it's about feeling not timing.