Wonder Woman is portrayed differently in every film involving Wonder Woman. Most of the older ones suggest that Wonder Woman thought that clothes woman wore were ridiculous. She made this conclusion when she looked at a short dress and a bikini in the Justice League animated series. She probably thought that woman wore dresses that showed off your body.
She must have also done it to look attractive to get away with doing stuff as, Batman/Bruce Wayne confirms that when he mentions that he would be the first man to let her get away because of her astonishing dress.