Sixth-plate, 1850s ambrotype of a child in the lap of a man, whose head and shoulders are covered by a dark blanket.
"Hidden Mother" photos are relatively rare and are usually found in the tintype format; this sort of hidden person image with a man holding the child are much less common, and particularly hard to find in ambrotype format.
This ambrotype has been sealed with an iron backing plate and is in a full case with matching cover and a repaired spine.