I think we may have stumbled onto a recent crime scene. There appears to be a clue hidden in the mirror and on the table. Look, a missing candle. Perhaps her husband Mr. Seville, the local barber, has done a dastardly deed and disappeared into the night with only a lit candle to find his way through the fog.
Her neck appears to be damaged and could that be traces of absinthe or arsenic in the glass. It is the witching hour and what was she thinking going out at this late hour. Perhaps to meet a lover?