When I was a young teenage mom, I recall my mother telling me that babies sleep that way when they feel content. I don't know how much *actual* truth there is to that, but it made sense.
well, not having proper joints causes the appendages to flay around at night, and babies can be found in all sorts of positions, so arms raised is just something that happens....
To stretch because they used to not be able to
Ahh yeah it does seem he is at peace.
i still sleep like that