I don't know, these observers don't really have a purpose for me. I mean if they're a type of time traveling tourist, like in the movie ''Grand Tour - Disaster In Time", they need to be a bit apart from the action, then being practically in ever other drawing or photograph of a historic event. In other words, they seem to have a type of *Butterfly Effect*, just by proximity. There should be very few recorded events with them, hanging around with others, in a detailed photo-opt.
In 'Disaster In Time', the observers were at a small motel, outside of the town where the disaster was suppose to strike. What foiled the whole thing was the fact that the motel owner had figured it out and tried to warn the townsfolk.