Trivia: When Gonzo is in the restaurant, he takes a photo of a man and a wife sitting at their table. The man whom Gonzo takes a photo of is Jim Henson, creator of the Muppets.
Trivia: The father and daughter we see in the park is muppet performer Jerry Nelson and his real-life daughter, Christine.
Trivia: Muppet performer Richard Hunt makes a cameo appearance as a taxi driver during the opening number of the movie.
Answer: As shown in Nicky's office, him and the models are professionals, judging from the different tools that they are using and a map of the Mallory Gallery. All they would have to do is watch and wait for the dogs to leave a specific area, and they would be able to get in because of how quiet they were while Kermit and friends were caught because of how much noise Animal made while trying to eat through the bars.