"Dot Bridge" refers to a series of animated shorts produced by Clark Gesner for the first season of Sesame Street, first seen in the premiere episode. In each short, a series of 30 dots appear on-screen, often with various complications impeding the process. The series was meant to teach children "pre-reading skills by training the eye to take in information from left to right, or as one reads on a page."
The shorts were used as transitions between segments and continued to be shown irregularly on the show through the early 1990s. In many of its later airings, the colors were altered or changed depending on the episode.