What's the Third Possible Interpretation?

There are three possible interpretations of the phallus found in Pompeii. The first is that it's a separately carved phallus added to a larger object. A second could be a vessel, like a mortar and pestle set for grinding up food. It would be great if we could see examples of whatever ingredients materials were being ground up. But conservation process completed back in 1992 means we can't do any sort of scientific analyses for biological traces.