I was somewhat trepiditious coming to this after The Handmaid's Tale, which, whilst very good, I found to be heavy going. However, Atwood gives the ghost of Penelope a very modern, chatty voice which is very easy to read. Since the book is also short, this disappeared very rapidly!
Penelope delivers a monologue occassionally interrupted by a Chorus - which is the exact structure of early Greek drama. The Chorus consist of the ghosts of the 12 Maids hanged by Odysseus and the book is as much about them as Penelope in some respects.
There's a common theme across this and The Handmaid's Tale of women rendered powerless by the society they live in but trying to assert their humanity nevertheless.