One of the delights of any of the Wallace and Gromit stories is the number of in-jokes that the film makers can incorporate into the plot or, more often, onto the screen. The first was big and, to many, pretty blatant. The co-writer of A Matter Of Loaf And Death with Nick Park was Bob Baker, one of the co-creators of Doctor Who's (or now more accurately Sarah-Jane's) K-9, so it was really no surprise that the first of the bread bakers to be killed off in the story was Baker Bob.
That said the best of the in-jokes for me was when Fluffles the poodle returns Gromits's things to him. In the box amongst vinyl records by Doggy Osmond and McFlea and a soft toy Bagpuss is a comic. Gromit reads The Beagle and the prop is complete with accurate Eagle title box and title font.
It is the little things like this that make Nick Park's two best known characters such a delight to return to time and time again.