Need a better picture, but is that a beer tap? It looks like a coil of pipe in the bucket. My guess would be you fill it with Ice and connect it to a keg. You are probably missing a lid too... Just a guess, good luck!
Thank you. I agree that it is part of a beer tap. I had a feeling but I've never seen it before. My uncle hosted a lot of picnics back in the day. He also has this cooler that has a tap on it and coils on the inside. My brother and I remember that one having a CO2 tank but we can't find it. Worth anything to anybody?