Luke 2 describes the same event from two vantage points.
From an earthly perspective...
"the time came for her Child to be born. And she gave birth to her firstborn, a Son. She wrapped Him in swaddling cloths and laid Him in a manger, because there was no room for them in the inn."
From a heavenly perspective...
"And suddenly there appeared with the angel a great multitude of the heavenly host, praising God and saying:
“Glory to God in the highest,
and on earth peace to men
on whom His favor rests!”
This heavenly perspective is echoed again in Rev 12 as a "great sign" in heaven of cosmic implications, the birth of One who will rule the nations.
Momentous activity in heaven can appear very subtlely on the Earth.
"Your kingdom come..."