The cartoon is itself a subtle send up of the shorts shown as part of the usual cinema programs at the time. These included a newsreel, a short feature (travelogue, etc.), the actual film...and a cartoon.
Said to be the inspiration for the future cartoon duo of Sylvester and Tweety.
Catty breaks the fourth wall in a cleverly animated way.
The title is a pun on the Scottish fish dish Finnan haddie.
Included as a bonus on the Warner DVD of Old Acquaintance (1943).