When the family drives over to the park for the picnic, they seem to be driving a larger station wagon than the compact car seen in previous episodes, such as Are We There Yet?, or My Pet Elephant. Did they get a bigger car, or did the artist just make their old car longer?
Even though the event is being billed as the Glover Family Picnic, they must have decided to invite both sides of the family, because Aunt Debra is Brenda's sister, noted by the physical resemblance.
Although it may have been implied in previous episodes, this is the first time we find out that Uncle Al is Big Bill's brother. (As opposed to being Brenda's brother, or Vanessa being their sister.)