Pay attention to the ARTISTIC REPRESENTATION of the human face/body in these paintings, and how it differs from the ones right next to them, and even more from the ones further away. Some go for versimilitude, or strive to attain it at least, others never try to go near it and instead propose a very personal INTERPRETAION of the anthropomorphic representation, more personal, more simplified/stereotypical, or on the contrary a more complexified/transmuted version of a human figure. Same goes with the art of Mise en scène in cinema, and we see the same affinities and contrasts between various branches of cinema history, the realists, the verbose, the minimalists or the abstracts... (to cite only a few of them possibilities discovered by filmmakers over the years).

(Source: http://screenville.blogspot.fr/2012/12/cinema-aesthetic-matrix-paintings.html)

You should not be stopped by that. Messiaen is such a complex figure that you should forget all about the religious approach. He is very sensual, in his music as in his life. His first wife went crazy or something and he married after a while a young pupil, a pianist called Yvonne Loriod; they are passionately in love, together. And this is a sin. And his music is a sin, too. It is also - also - very abstract in its scales, a very intuitive departure from the traditional scholarship into the realm of rhythmics, Indian, Greek, very pagan.” — Iannis Xenakis, a general nonprogrammicist, who was taught by Messiaen, argued that catholic mysticism is irrelevant to Messiaen’s music.