There was moving pictures of Russell speaking, probably at the beginning and ending and intermission, which was synchronized with the recording of his voice. There were moving pictures of various Bible scenes, during which recorded music was played. Color slides were shown while recordings of the text spoken were played.
The full Photo-Drama took 8 hours, but there was a shorter version called the Eureka Drama. This might have just been the slides.
More information on the Photo-Drama can be found in the Watch Tower from that time. It was very expensive, and many volunteers were needed to run the slides, and the moving pictures, and the recordings, etc. It was shown throughout the world to many viewers.
The Photo-Drama was probably Russell's most ambitious large-scale undertaking, which needed large financial resources and willing volunteers. It is true that there is propaganda mixed in, but it should recognized that was perhaps Russell's most mainstream effort, and much of the music and art was of good quality. It is one of the most positive things about Russell and the early Bible Students. In fact, the Russell's early Bible Students were moving toward the mainstream, and the PhotoDrama is a prime example of the move to gain respectability. The Bible Students/JWs perhaps never equaled the Photo-Drama in popularity, artistic excellence, and effectiveness as a public witness. However, Russell's failed predictions, the confusion surrounding 1914, Russell's death, and Rutherford's rise to power all worked to regrettably reverse this mainstream trend, and the Bible Students became more narrow and eccentric.
