What the first result is returning is keyworded based on art discussions about European works. Relevant articles discussing the uniqueness of portraits of black people in rennaissance paintings are the results you're seeing. Likely it's the inclusion of "people" which is throwing the results, as you see a much "whiter" result set if you search "portraits of european" (plural or not doesn't matter). In fact, for the original search if you scroll down you begin to see the paintings and portraits you are expecting to see.
Basically, it's just keywording providing results you weren't expecting. The word that throws it is "people".
Edit: and in regards to why Yandex isn't showing it, it's because the top hits are from a russian artist's site, so they're just weighting russian sites higher. For whatever reason, people clicked to these images when they searched it on Yandex.
This is a non-story.