This is probably the back porch of the building in the previous image, with Annie teaching ladies to shoot. They look (from left) to have a revolver, a lever action, and 2 possibly Remington Model 12 .22s which Annie was known to use. Annie is 2nd from right
As said, there have been lots of sighting devices for the muzzle.
1894 Parker D Live Bird Gun courtesy of Gordon Lew
Wilbur Gun Sight is the only one I've found for the breech
October 1919
Forest & Stream https://books.google.com/books?id=F99JAAAAYAAJ&pg=PA568