@onceuponatime plagiarism is exactly related to the lack of attribution, the same work with attribution of sources, stops being plagiarism. If I say I drew a portrait, and I dont cite an image source it is assumed I made it from a live model or from a photograph I took.
If it was made from a photo someother person took and as in this case I copy exactly the whole composition and not just the face, without crediting the photographer its plagiarism, a specific type of plagiarism called art paraphrasing. You can learn more about art plagiarism here: https://steemit.com/abuse/@jaguar.force/what-is-art-plagiarism-by-francis-leverett-golden