Is seeing a movie the same as seeing a play? Watching a concert the same as listening to a CD (or a 33 rpm record)?
Similarly, seeing a talk in-person has differences versus watching a video. Bear this in mind when evaluating a video of a talk. Is the talk you are evaluating intended to be in-person, a video, or both? A video talk might be intended to be performed one-way (broadcast TV or a video distributed for viewing later), partial two-way (broadcast webinar where the audience might ask questions at particular times), full two-way (video-linked meeting, Skype). Is it a final product, or a practice, in which case the audience might be missing?
In-person: speaker and audience members react to each other, explicitly and implicitly. An audience member feels how others are reacting – visual cues, sound, maybe even touching or foot-stomping vibrations. The speaker sees and hears the audience. Positive synergy can (and should) occur.
Video (speaker with no audience): there is no speaker-audience interaction and you, the evaluator, have to account for that. Is the final product to also be one-way video, or might it be in-person, both in-person & video, partial two-way video, or full two-way video? Couch your coaching accordingly.
Video (speaker in front of an audience you can’t see): you, the evaluator, have limited clues on how the audience is reacting.
Video (speaker in front of a visible audience): you can see the audience. Depending on the sound recording (such a mike on the speaker) you may hear little of the audience reaction. You will get little, of any, of the group synergy of an in-person audience.
Consider sharing with the PostAndCoach audience (by leaving a comment here), your observations of experiencing a talk in-person versus watching a video. In particular, how can a speaker adjust accordingly?
Example 1: The quality of a video with regard to lighting on the speaker seems (to this commenter) to be more important than when in-person. A video watcher is in a room with ambient light different than where the video was taken.
Example 2: A video speech looks different if it is just a single fixed view of a stage, or a multi-viewpoint professional edited video.
Example 3: A video speech looks different if one can see the speaker’s face up close or just a body on a distant stage. Compare what you are evaluating versus what the speaker might be practicing for.