The light slapstick and the contemporary footage of the San Diego Exposition make this watchable, but it is most interesting for its improvisational approach and for its unusual blend of fantasy and reality. Although numerous other Roscoe Arbuckle/Mabel Normand features are more enjoyable in themselves, this one is unique in its way.
Mack Sennett sent his two stars to San Diego, and placed them in a semi-staged, semi-spontaneous situation in the midst of the crowds and attractions of the exposition, as much to promote the exposition as to create comedy. Arbuckle, Normand, Minta Durfee, and a handful of other Keystone performers see some of the sights and then get involved in some slapstick predicaments.
In the opening scenes, Arbuckle and Normand are more or less simply appearing as themselves. Gradually a story of sorts begins, with Arbuckle playing the role of a shameless flirt, and Mabel the jealous woman who decides to teach him a lesson. It plays out against the background of the crowd that was there that day, and it has the stars interact with some of the exhibits and performances at the exhibition, with one of the longer sequences taking place at a hula dance performance.
Arbuckle's unsympathetic role limits what he can do; he does his job effectively, but aside from a couple of displays of his agility he never gets the chance to do very much. This isn't Normand's best role either, but she gets to do more, and as usual her gestures and facial expressions work very well as slightly exaggerated comic outrage. Some of the slapstick works well, although at other times the largely unplanned format keeps it from jelling.
The most interesting thing about the movie is that there is never a clear-cut transition from the actors playing themselves to them playing their characters. Likewise, it's not always easy to determine how much the crowd expected, and how much records their honest reactions to the actors. Sennett, of course, hardly meant this as a philosophical statement, but it is still a very interesting example of the kinds of themes involving fantasy, reality, identity, and art that for the most part were not taken up by film-makers until much later.