One is the story telling. It is an absolute must in video and nothing we did in still prepares us for that. Oh we thought we were telling stories with still projects, but compared to video it was like telling a story with a few pretty phrases thrown together. We rarely ever did still photography to the level of full sentences. We never really got to the point of full paragraphs and certainly weren't at the level of chapters organized into a book. Still photography can only show frozen moments of any story. To tell a full and flowing story in video takes a very large learning curve.
Cannot be emphasied enough. I learned to write screenplays a while back and only then did I finally 'grok' filmaking. Everything, absolutely everything in film production is subservient to the story.
Well to clarify, it should be, sadly often isn't and that's why so many bad films get made.
The other point I'm seconding it that of sound. We do underestimate that in video and have to learn the hard way how important it is. Capturing it and editing is another learning curve for still photographers. It gets even more complex when you realize how critical sound is to the story telling.
Get the sound right and the photography looks better. Easiest way to make a film bad is to mess up sound.
Technically poor photography can be part of the story telling, technically poor sound, just seems bad 99% of the time and cheapens entire production.