Imagery from Stereo spacecraft apparently.
Where is that? Suppsedly near LaGrange point to observe Sol?
Anyway the artifact does move through the video frame BUT size cannot be inferred. Video calls it "HUGE OBJECT" but unless they know the distance, they can't properly infer that. Could be small dronish size object passing very near to the satellite.
Or what's the chain of custody, so to speak, from the detector to the bits to the transmission to the storage to the playback? Is there opportunity for a digital video artifact to be introduced somewhere along that data path and who would be motivated to do that?
Anyway……….