I love this painting. Mary sees the angel but she doesn't interfere. She makes no move until Joseph wakes up and tells her that an angel told him it's time to put on their traveling shoes again and Baby Jesus, who is perfectly capable of commanding, "Herod is after me. My Father will deal with him later but right now, you need pack up and get us to Egypt," does not. He trusts Joseph enough to let him do the job God gave to him. It's a rich scene to meditate on.