Tornadoes producing a "dead man walking"

The image above is from a video on a television documentary about tornadoes.  Twin twisters rotating about one another produced a figure that could be viewed as humanoid in shape.

A discussion thread at the extensively-redacted AskHistorians subReddit examines whether or not there was a legend among pre-contact plains native Americans of some tornadoes being referred to as "dead man walking" and whether this image is representative of that.

We have often wondered why tornadoes are not depicted in ancient rock art petroglyphs in North America.