Even if this was work from author, he himself made a mistake. He gave Matsumoto almost the largest breast in the show but when she is in bikini, he shrinks them?
If her breasts are drawn incorrectly, then the author obviously did not draw her. This picture (& Orihime) is from a set of cards distributed by Dentsu. A manga-ka does not have time to draw for anyone but his own manga.
Breast-reduction is an obvious form of censorship by the advertising agency. Still looks good though, no?
