I think that Visual Anthropology include pictures and videos, and even pictures in a poem there. but the movie is a documentary film about people and culture. We see the images that are in the field of visual arts. Like paintings and photographs and even paintings and calligraphy, and graphic symbols on road traffic.
So I suspect that there is a unique documentary film genre. but there is a vast and wide visual anthropology.
Plato defined time as a moving vision of eternity (Timaeus). From this definition we can learn a difference between visual anthropology and documentary cinema. Film sets in motion what is a static testimony on the life of man (or visual anthropology). Anthropology has as its goal a permanent statement about mankind, whereas film provides temporary evidence limited in and by time and space.
Visual anthropology discovers naturally occurring patterns with still shots. Documentary photography is content rather than shape form at aesthetic driven, as I understand it.