Your Mona Lisa example is different in that you are talking about a physical alteration of an artwork. Both sculptures occupy different spaces, which happens in this case to be a shared public area where the bull was never given permission to be there. Do Modica cannot choose to prevent other people from reacting to the bull differently from what he intended — after all, that is the nature of art. In this case, the placement of the Fearless Girl is one such reaction. I agree with the others who had suggested that Di Modica should remove the bull if he cannot tolerate this — to a private gallery where he can control the environment as much as he likes. It would, however, give the Girl figure more power in her narrative, that the bull was faced down and went away.