You might well have seen the occasional item in Topshop from Sister Jane. In fact, if you have, it probably looked like it might be a vintage piece, which is pretty much the style of the label. This Sacred Heart Lace Dress typifies the look.
You can take your pick between a framed version of one and an unframed print of the other 1960s Andy Warhol exhibition posters here which has just been reissued.