This is ...

This is a newborn baby’s visit to a Shinto shrine in Japan.
The period for visit depends on convention in a local area such as 33rd day after being born or 50th day etc.
When a family with a new baby go to a Shinto shrine,
a boy wears kimono with an eagle or armor embroidery
and a girl wears kimono with a flower or car for the Imperial palace embroidery.