LOLSaints

...and Joseph is a good Dad, too!

[This is a beautiful representation of the Holy Family, especially since we are rarely given beautiful art to contemplate that includes all three members of the Holy Family performing a task so normal and so human! —Ed.]

What is the significance of the mention of Christ being wrapped in swaddling cloths?

It is to show that He is the son of David.  In Wisdom of Solomon, Chapter 7, Solomon recounts how though he is the greatest of all the kings of the earth, he was born like all others:

"And when I was born, I began to breathe the common air, and fell upon the kindred earth, and my first sound was a cry, like that of all. I was nursed with care in swaddling cloths. For no king has had a different beginning of existence; there is for all mankind one entrance into life, and a common departure."

Jesus' humble birth is a sign that he really is the true Son of David. Like Solomon (before he fell away from the Lord), he is not about power, might or glory. Indeed, it would seem that along these lines the fact that he has even more humble birth might suggest that he is somehow even more worthy of glory. And, of course, he too is wrapped in swaddling clothes.