The woman is perfected.
Her dead
Body wears the smile of accomplishment,
The illusion of a Greek necessity
Flows in the scrolls of her toga,
Her bare
Feet seem to be saying:
We have come so far, it is over.
Each dead child coiled, a white serpent,
One at each little
Pitcher of milk, now empty.
She has folded
The poem moves from imagery of a perfected dead woman to serpent-like dead children.  When seen as something outside of Plath’s personal life, this line could be understood as mid-century  social critique of feminism .  Children are not only absent, but like a serpent they are a threat and a risk to women’s liberation. 
 Note that white serpents are symbols of purity and positive energy.  Therefore, Plath may see her children in this way, a positive factor in her life. 
 Alternatively, another strand of feminism accepts the biological fact that women are child-bearers and sees it as a strength; a source of power as women can then most influence children to grow and fight the subjugation of previous generations. As with many of Plath’s poems, this is full of contradictions. 
 Yet another interpretation is that this is a reference to Shakespeare’s  Antony and Cleopatra , where Cleopatra killed herself by obtaining an asp which bit her. 
 Dost thou not see my baby at my breast, That sucks the nurse asleep? 
 Within the context of her life this may also be symbolic of her multiple miscarriages. Also, her use of color in every poem is important. White in her poems typically represents emptiness; echoing perhaps an empty womb. “White serpent” could also be viewed as an  oxymoron , as white has connotations of purity, but, particularly through a biblical lens, snakes are portrayed as representing sin and the devil (e.g the snake in the garden of Eden). 
 There is also a suggestion that the dead children could represent the Greek tragedy ‘Medea’, in which the heroine kills her own children. It has been suggested in some biographies that Plath might have contemplated killing her two children when she committed suicide.
Edge