Besides being a rather tantalizing piece of movie history, this is a fun and well-crafted short feature in its own right. The idea is very simple, but it is pulled off flawlessly, with special effects that are excellent for its era, and with plenty of good-natured energy from the numerous stars who appear in it.
Carter DeHaven sets things up by announcing a series of 'impressions', which then introduce appearances by several of the biggest film stars of the 1920s. A number of them perform brief but wonderful trademark bits: Harold Lloyd does the little jig from "The Freshman", Roscoe Arbuckle (looking much thinner as a result of his legal ordeal) does a frying pan gag, and Douglas Fairbanks appears as a swashbuckling Robin Hood. It's great fun just to see these and other brief appearances.
The movie's historical background is equally interesting. As other reviewers have noted, the original date can be determined with a little detective work, and Richard Roberts's commentary on the Laughsmith/Mackinac Media collection of Roscoe Arbuckle movies is well worth listening to, for all the fascinating details that he points out.
But really, you don't even have to care about the background all that much in order to find this miniature feature a pleasure to watch.