In the YouTube Trailer for the PBS program A Year in Space at
00:56 a small spinning object can be seen, attached to a spacecraft well above the ISS. I think the video is significantly speeded up so the object looks blurred.
It reminds me a bit of the RapidScat (shown below), a microwave scatterometer that measures near-surface wind speed and direction, mentioned here and explained here.
Is this an antenna of some kind or something else? What spacecraft is it attached to?
below: GIF from the YouTube Trailer at about
00:56. The motion is clearer in the original video linked below it.