Hello,
This appears to be a bad appeals decision to me. You even note the artist in the description, and included a link for the art piece and notes from the artist in your appeal, although for what appears to be the original art piece in a building, not the utility box.
Hopefully staff can take another look at this. Tney have instructed us to post about what we believe to be bad appeals decisions here.
Edit: Just looked at this on Google Maps and Street View, and it’s hard to tell if it’s on private property. I see a driveway to PRP just north of the box, and while a business is listed as being there, it could be one run out of someone’s home. This is noted about areas outside of PRP, which is why I now have to question it: