Poetry of the Confessional Poets is all about personal experiences and typically dealt with themes such as death, depression, trauma, and personal relationships. These were new subject areas in literature given that many times texts were not typically written from such an honest and open first-person point-of-view. In this type of poetry, authors dealt with very personal and sacrificial writings in which, basically, they "spilled their guts".
Confessional Poets emerged during the 1950s and 1960s. The most famous of the Confessionalists were: Sylvia Plath, Anne Sexton, John Berryman, Robert Lowell, and L.D. Snodgrass.
The imagery of the Confessionalist's was typically dark and depressed. These authors had no interest in hiding the truth behind the reality of their lives. Perhaps they looked at their poetry as a sort of way to deal with what has happened to them and as an own personal therapy session to heal.
One example of a Confessional Poem is "Barren Woman" by Plath
Empty, I echo to the least footfall,
Museum without statues, grand with pillars, porticoes, rotundas.
In my courtyard a fountain leaps and sinks back into itself,
Nun-hearted and blind to the world. Marble lilies
Exhale their pallor like scent.
I imagine myself with a great public,
Mother of a white Nike and several bald-eyed Apollos.
Instead, the dead injure me attentions, and nothing can happen.
Blank-faced and mum as a nurse.
The imagery here is forced upon a reader through Plath's imagery ridden terminology: empty, echo, sinks, blind, pallor, dead, injure, nothing, blank-faced, and mum.
All of these words depict sorrow, solitude, and pain. This is an example of the way imagery is used in the poetry of the Confessionalist's.