The Brady Bunch Closing Credits Season 1

What's strange about these closing credits of the Brady Bunch (other than the fact that the characters are encased in boxes and looking straight ahead)?

Answer: the film is forwarded and rewound at approximately five-second intervals, and the characters' heads bob and then repeat.

Pay very close attention to Ann B. Davis' eyebrows and you'll see what I mean.

Can't beat the cheerful closing theme though. It's so joyous, like a parade in New Orleans.