This example is a bit more oldschool. Most of the examples on this blog are from the modern era where it’s so easy to just take any image from Google or Instagram and use it for your own gain without crediting the source. Obviously plagiarism is not limited to the modern day, though. The trick with plagiarism that people seem to get confused about is that it takes many forms.
In this day and age, many people would say, “Well, at least the artist painted it himself!”. True, he did paint it, it doesn’t even appear like he traced it. But the composition, palette, character, concept and style is completely stolen. He didn’t just use the pose for reference (which would have been fine), he just took it all.