Universal's Promotional Handbook for Exhibitors calls this a "Herald" and a "ROTO." The "Super-ROTO" that accompanies it was intended for distribution through the mail, or on the counters of hotels and diners. The word "Supplement" in the title of this four-page, three-color flyer, though, suggests it was meant for distribution by way of the local newspaper. Its text emphasizes both how much the story of "Uncle Tom's Cabin" is a national one, and how much Universal spent making the movie. Larchmont is probably the town in New York, but the flyer was used across the country; the red ink indicates the parts that were printed locally.
For all its Hollywood hype, this ad actually includes a passage quoted correctly from Stowe's novel—the caption under the drawing of Eliza crossing the ice contains the first three sentences of Chapter 8 of Uncle Tom's Cabin. The scene of Lincoln with Generals Grant and Lee, on the other hand, not only isn't in the novel. It's not in the film, though it was used several times by Universal in their promotional materials for the film.