I just saw the post on Facebook. They look very good to me, I think the simple guess is probably right in this case. Photos taken by a team member with multiples created for other team members and the like (their families as well as just extras). It would be nice to see some angled photos outside of the plastic though, 1919 these should have some silvering to them if they're double weight. But they may not be, hard to tell.
Here is the link, not sure if it will work. Facebook really sucks at sharing posts.
https://www.facebook.com/share/p/17FJrNLTmt/