This Powers Universal Comedy from 1912 has a very simple premise: a family is going to have the pictures of the two youngsters, a boy and a girl, taken by a photographer. Nothing bizarre takes place, there are no unusual gags, yet this is a very funny comedy: the children torment each other -- and the photographer -- in a highly naturalistic manner. As Mel Brooks has noted, if I cut my finger that's tragedy. If you fall into a manhole and die, that's comedy. Although no one dies in this one, it is comedy.
Very little is known about this film besides its release date (listed as May 12, 1913 in the Slapsticon 3 (2005) program book. If the opportunity comes around for you to see it, take a few minutes to do so.