The BBC News item UK satellite to make movies from space describes this newly deployed satellite:
caption: Artwork: Manufacturer SSTL calls it Carbonite-2, but Earth-i refers to the satellite as VividX2
According to Gunter's Space Page it has a 25 centimeter aperture and at about 500 km altitude should have a ground resolution of about 1.5 meters. However, according to the BBC article:
"We can collect up to 50 frames per second which is a lot of information," explained Earth-i CEO Richard Blain.
"That allows us to stack the individual images and increase our effective resolution, achieving somewhere around 65cm to 75cm," he told BBC News.
How would a high video frame rate improve ground resolution to 65 centimeters for a ten-inch telescope at 500 km?
I have heard of techniques such as "lucky imaging" (it's a real thing) but this is usually to combat atmospheric seeing effects, not the diffraction limit. Also, this excellent answer points out that atmospheric effects are much less important looking down at the surface than looking up from the surface for apertures well below 2 meters, confirmed by this answer as well.
So here, I don't understand how the high frame rate can have such a profound effect so as to push well beyond the Airy Disk diffraction limit of say $1.22 \lambda / D$ which would be about 2.7E-06 radians, or 1.36 meters at a 505 km closest approach (assuming a 550nm central wavelength).
There are other techniques to push beyond this limit, such as Aperture Mask Interferometry as described in this answer, but that wouldn't be related to high frame rate.