feed on the emotion Love, so they feed on it through psychic powers, and if Love was liquid it would maintain a glowing radiant magenta color, so Love is dis proved, so the contents of the glass indeed a liquid, but since its a wine glass, it's reasonable speculation that the liquid you is is wine. That is my clever deduction.

Let's see, we can already dis prove it being blood, since blood is exactly 19 shades darker. And changlings