Graffiti tags like this are typically considered vandalism, and are not eligible as a result of that. I’m surprised it got accepted, as it realistically should’ve been rejected. You can read more about that here:
Even if it was eligible though, judging by the location pin in the screenshot, it seems like it’s probably too close to “Mural ComeMundos” to be used as a Pokéstop or Gym. You can read more about the density rules that Pokémon Go uses here: