Not sure... But I think it is in reference, to the sound and activity of a group of school girls
passing the latest gossip about their classmates, boyfriends, etc... Sorta like a, whispered
Tee Tee giggle, Tee Tee giggle giggle, kinda thing.. If ya get what I mean?
That comes from my youngest son, who says.. "School girls Twitter, MEN DO NOT!!!"

I raised him well!!!!
RC