If it's no more than the fan to the face, it means "I wish to perpetrate violence against you." If it's a fan to the face accompanied by screaming and running away, it means "There's a spider on your face!"
Of course this "language of the fan" would have deserved more laughs in an 18th century "salon", and DID NOT exist ! Nobody has been able to find a proof of such a language at the time evoked by the dress shown here, with talent and humour.
