I think the boy on the right is not happy with the wobbly and precarious seat given to his sibling. He is clearly holding onto the child behind her (?) back to keep her from falling. I think the seated baby is a girl because of the rather large necklace she is wearing. You can see her bloomers peeping out from under her skirt too, which is insanely cute. The boy’s dress is a hybrid between skirts and short pants. He might have going through the potty training stages, which merited short pants, but still had accidents which merited a skirt.
I can’t read the name of the photographer. Any guesses?
UPDATE: Iggy found a photographer named Jacob Esterline located in Scranton, PA between about 1870-1915. This card is a dark maroon, which gives us the dates of 1885-1895 for this photo.