Yes....there was a Very Frequent Poster in these threads, I forget who, who kept calling Bonin's SS technique "stirring the mayonnaise." It should be reminded that such a technique is much more dangerous/critical at high altitude/speeds.
The pilot appears to be moving the stick quite abruptly. I think this looks strange to some extent because of the wide angle lens being used, and also the fact that the camera is attached to the airframe. The extreme lens perspective makes the plane's flight appear extremely smooth. I think that if a more normal lens were used, perhaps handheld, we would see that there is some turbulence, the flightpath is in fact not quite so smooth and that the stick movements are not extraordinary.
Besides - Boeing pilots seem to move their yokes around quite a bit as well, see around the 5:00 mark:
Cockpit video - Boeing 737-200 - landing at windy Cancun, Mexico. - YouTube
If SS 'stir the mayonnaise', what do yokes do? Tumble the laundry?
