These are seniors from the Desert Vista High School in Phoenix, Arizona at a photoshoot for their year-book.
Probably nothing more than the infantile humour that 18-19 year-olds are so fond of. The “seniors” tag hardly seems appropriate. Yet, nothing that a good spanking or a day in some public stocks wouldn’t cure.
But then, that would be sexist.
Of course it could be, that these girls are just so dumb (hardly innocent or naive), in spite of being “seniors” at a “high” school, that they don’t even understand that white girls spelling out “NI**ER” is more sinister than just stupid.