The video essay is as hard to define as the essay film is, since it is still in active development as a format for critical thinking. Better not to define it in too strict a way then, because the many emerging formats and practices may very well trump any strict definition.
In general, the video essay can be described as the concise, free-form audiovisual equivalent of the written essay. Concise because most video essays don’t run longer than a handful of minutes. Very long video essays are the exception to the rule that on the internet (the natural habitat of the video essay) shorter is better. Free-form because the format and rhetorical strategies can differ wildly from one video essay to the next.
What about content matter? The term video essay has come to denote primarily a video in which its maker analyzes or comments on a specific film or television related topic or theme. It is a concise and personal movie, focussing on a single aspect of (often popular) audiovisual culture.
However, the video essay can be the ideal vehicle for critical thinking about film, for reflecting on movies in their own language and format. Which is why this practice has been adopted by both film critics and by film scholars.
In his research note Film criticism, film scholarship and the video essay, Andrew Mcwhirter makes very interesting observations about both the essay film and the video essay, about their affinities and shared lineage.