Di Modica has referred to his Charging Bull as “art”, while Fearless Girl is an “advertising trick”.
BOTH of these sculptures can be rightly called “advertising tricks” (whether either of them is “art” is in the eye of the beholder).
Also worth noting is that both Charging Bull and Fearless Girl are guerrilla installations, installed without specific request or permission by the city. Just because Charging Bull was first doesn’t give Di Modica any special rights as to whatever other guerrilla installations are made in the vicinity. If he doesn’t like it, he can move his bull.