This montage of different images is an example of a derivative work
Derivative work is a phrase used in copyright law. It is a piece of work (for example: a novel, a song or a painting) that is based on what someone else created.
Copyright law says that if someone writes a book, draws a picture, or writes a song, then it belongs to them. Other people are not allowed to copy it unless the person who created it says that they can. This is important because it means the person who created the work can sell what they created and get money.