The countess is putting on a new dress and is about to also put on some rich ornaments. On the chest are a brush, mirror and death's hour glass. The hourglass symbolizes how short life is and serves as a memento mori.
But the woman does not realize that her time is up. She is preoccupied with her new finery. Even as she revels in the pleasure of trying on a new dress, Death is standing behind her and placing a necklace of bones around her neck.
Previous: The Old Man
Next: The New Bride
Holbein - the Dance of Death.