This woodcut, the work of the semi-anonymous "Italian Monogrammist" and printed around 1510, shows the newly arrived Christ in the arms of his mother, taking the airs outside the stable. What is unusual to me here is the attitude of St. Joseph, who adopts a dictionary-ready pose of nonchalance: he is leaning against a tree, his left arm propped up at the elbow on a tree limb, his feet crossed at the ankles, with a look of I-don't-know-what on his face.
He is definitely not of the standard Josephs that one sees in this scene.Perhaps he is communicating a certain type of tiredness, but I doubt it. The man is staring off into space, not looking at wife and baby, not looking at the many visitors coming through the tunnel in the mountain and excitedly rounding the nearby turn in the road, not looking at anything that we can see. He's not seeing the invisible stuff either: not the praying angels and not the sun-ray daggers.He's not tired, not excited about the baby and wife, not excited about the visitors, and in a pose of resident uncaring relaxation--boredom might be the easiest and best explanation, except, well, it doesn't make for a good story.