As @l'électeur asked, what is the context?
- It could mean
This is a Video, isn't it?
- It could also mean
This is a video
as if introducing some long lost technology.
- It could also show some kind of small astonishment like having found a video where they were expecting something else
Oh! A video!
- When addressing something you are confident is a video, without wanting to offend another person's interpretation of the object
This, as you may already know, is a video
- Realisation that you are being recorded rather than photographed
You are taking a video right?
- From the view of the person taking the video
I'm recording!
(implying that a video rather than a photo is being taken - as with the photo/video element of digital cameras and phone camera/video recorders)
The ね
is either implying a question where agreement is expected (as in the first example).
Implying solid understanding of the subject (That is definitely a video) as in the second example.
Indicating a small amount of astonishment (as in the third example).
Without intending to cause offense at stating an obvious fact (fourth example).
Questioning the state of something and expecting an answer (fifth example).
Softly stating a fact that others may have not been aware of (sixth example).
EDIT to include @Michael and @user224579's comments
Once again, without more background it could mean anyone of these things and/or more.