Most woodworkers think of a block plane as a hand plane about 6″ long without a tote (rear handle) that can be held in one hand easily. (Most non-woodworkers call this a “planer” which, to woodworkers, is something else.)
One definition of a block plane is a hand plane with blade installed on a low-angle bed (commonly 12 or 20 degrees), bevel-up. By that rule, this Primus 6″ wooden plane, made by E.C. Emmerich Company, whose blade is installed bevel-down on a 50-degree bed does not qualify as a block plane, yet it is described as one. Yes, it is a small plane easily controlled with one hand.
That rule does include low-angle (bevel-up) smoothers, jacks, and jointer planes in the category of block planes. This is how Lie-Nielsen Toolworks, Inc. classifies their planes. That means each of these planes could be called a block plane.
But I cannot think of any way to stretch the definition to include a plane such as this one. Can you?