Burgfräulein von Strechau, by an unknown artist from the 17th century. The painting hangs in the Kunsthistorisches Museum, Vienna.
The legend (as far as I can determine from the German websites I’ve deciphered with the help of Google Translate) tells that in the late Middle Ages a damsel waited for her lover who left to the Holy Land to fight the infidels. The lady promised that if he did not return she would enter a monastery. Despite her promise, she married another man and when the bride came to the festival her face changed to a skull and devilish figures appeared and pulled her down to hell in front of all the guests.
The legend is derived from a poem.
This is also a good photograph of the painting, via Flickr.