These incredible works of art seem to be hybrids of statue and triptych. This style of art was apparently popular (at least for Our Lady) in the 15th and 16th centuries.
These pieces are called "Vierge Ouvrante," which roughly translates to "The Opening Virgin." They are also known as "Madonna Shrines."
Images inside these triptych statues include scenes from the Passion, Mysteries of the Rosary, lives of the Saints, and Old Testament stories.
Seriously - aren't these the coolest things ever? I want to commission a new set for myself. Ha ha.
The idea behind these is wonderful. God - the Eternal - is within each of us. However, He was, is and always shall be fully present within Our Lady because of her perfect Fiat. Our Lady, through the Annunciation and Incarnation, became Mother of the Eternal. Within her womb she carried the Fount of Life which cannot be constrained by place or time. Through her, we can know God. Through her, we can find the path to Christ.
Really - I am in love with these!!! I think they're absolutely brilliant!
Hail, Mary, beloved Daughter of the eternal Father!
Hail, Mary, admirable Mother of the Son!
Hail, Mary, faithful Spouse of the Holy Ghost!
Hail, Mary, my loving and dear Mother, my powerful sovereign!
Hail, my joy, my glory, my heart and my soul!
Thou art all mine by mercy, and I am all thine. But I am not yet sufficiently thine. I now give myself wholly to thee without keeping anything back for myself or others. If thou seest in me anything which does not belong to thee, I beseech thee to take it and to make thyself the absolute mother of all that is mine. Destroy in me all that may be displeasing to God; root it up and bring it to nought; place and cultivate in me everything that is pleasing to thee. Amen.
--by Saint Louis Marie DeMontfort