Go ahead and learn more about art plagiarism here: https://steemit.com/abuse/@jaguar.force/what-is-art-plagiarism-by-francis-leverett-golden inform yourself about the true scope and shades of art plagiarism.

**Plagiarism is not only taking someones drawing/photograph/artwork and passing it as your own**, thats called art theft, and its only the most blatant form of art plagiarism, **the most common one is called art paraphrasing, which is what you are doing.**

If somebody gives you a picture so you make a portrait of them, thats a different thing, since they are the model on the photograph and have the right to use it.

In this case, the photograph is Copyrighted by the photographer, that means that the photographer reserves all the rights of the picture to herself, and that means that to make derivative works of that photograph, as for example Your Drawing, you need permission from the author to do so. Additionally since by posting it in Steemit you are monetizing it you also need permission from the author to do that as well.