When a girl sends the ? emoji, it typically means that she is unimpressed, bored, or annoyed. The eye-roll gesture that the emoji portrays is often used to convey skepticism or indifference towards something that has been said or done. It can also be used in a playful manner to indicate teasing or mild irritation. The exact meaning can depend on the context in which it is used and the relationship between the sender and the recipient.
