For some variation it would be better
to place the donkey seen from behind
[to avoid] all faces looking out of the picture [forward]
And the tree could also have more foliage.
1. Joseph has been portrayed too fat and too recklessly
2. Mary should hold the child more gently
because a vulnerable child can't stand being held so firmly
Joseph is too short fat - his head is growing from his trunk
and both [Joseph & Mary] their heads are too big.