They're both graffiti. Graffiti can be beautiful or art to some people or not be. But if the person did not build the building with that mural/art on it to star

They're both graffiti. Graffiti can be beautiful or art to some people or not be. But if the person did not build the building with that mural/art on it to start, or did it at a later date as part of the same project, it is graffiti in the modern sense of the word (in English). People thinking it is art, or thinking it is beautiful does not remove the aspect of it being graffiti. Even a large advertisement would be graffiti. I would hate to live in a building that had a huge mural go up after I moved in personally, but that also doesn't make it graffiti or not.