In fact we allow an unofficial poster if there is no official poster available, but it must be made from official materials (promo pictures...), it must not be too stylized (fanart, adding frames and various graphic elements), it must not contain additional data such as year, etc. (i.e. it must be a "clean poster") and it must meet our quality requirements (not blurred, not enlarged, etc.). So I deleted this poster not because it is unofficial, but because it is made from scaled up images and because it is too stylized (more like fanart).