Afterall Bruce Timm loved the first movie and is a fan of the comics as him and Paul Dini were inspired by both using some designs and character designs stuff with referencing the movies into the show including Joker's same coat/hat/suit like in the first movie to his phony fake name being referenced. Then in early 1991 during production of the show and while Batman Returns was being made the executives forced Timm and Dini to base Selina Kyle and Penguin off from Batman Returns still photos but didn't want to but they did and it worked like a charm.