In the past, these horns on display can symbolize a lot of things. They can symbolize the house owner's social status, wealth, or leadership profile within the community.
For some Cordilleran communities, carabaos are the preferred animals to be butchered in events like weddings and community feasts.
Once, during a hike in Kalinga, I asked a local man on the significance of the horns displayed on his house. I asked him in jest if he's the richest man in the village since he seems to have the most horns. He answered that he's not rich. He said he has many carabao horns because he married off three sons. So the horns were accumulated from three wedding feasts.
Many of these carabao horns are used purely for aesthetic reasons these days. You can see them now on display in restaurants, coffee cafes, in the bumpers of cars, etc.
📷 Joshua Jiggs; Photo taken in Belwang, Sadanga