I think it's solar powered. Once you start its head moving from side to side, if it's in the sunshine, it won't stop. It's charming enough, maybe, to make a young girl want to take it off the store shelf, but not engaging enough to be played with. So it stays in its box.
That's a cute little toy! The child in the background doesn't seem to interested in it, does it have batteries, does it do anything? I see Japanese characters on the package, but I can't read them.