It's sort of a "come-hither" look & pose, isn't it?
As it looks like it was produced professionally it was probably part of her portfolio for an aspiring modeling career, or something like that ... which is fine.
But apart from anything else, I don't think high school year books are an appropriate place for self -promotion. She probably has lots of such shots on her Facebook page which would suit that purpose perfectly well ..
I'm not shocked, horrified, outraged, etc, by the photograph
, but I don't really think it was the best choice for her year book image. I'm pretty certain it would not be accepted in any Oz school's end of year magazine (year book).