THM jpg image (movie clip preview)

[wolf]

Is it known how these images are created?
Are they generated from the movie clip or from the LV?

Edit:
I like to add that this downsized images are created on a 550D for the movie clip preview. Maybe on different models these images aren't created. I wonder if this could be a way to get an image without moving the mirror?

[Rush]

I wonder if this could be a way to get an image without moving the mirror?

ML Silent Picture feature takes images without mirror.

[1%]

The thumb image is created when all of the other meta data is written and the movie becomes .mov from .dat