This card is the exact size and paper type as a postcard, but blank on the back. This product of the Exhibit Supply Company of Chicago is actually what is known as an arcade card. The arcade machines (here’s a list of the many machines that were produced) would, on deposit of a coin, allow you to play a little game, or watch a mechanism do something, and in the end you’d get an arcade card or a piece of candy or whatever.
This card is unsigned, but the style of those babies seem to be the work of Fontaine Fox. The widow is less ‘Foxy’, so I’m not going to claim to be sure.
The card is undated, but I can’t imagine Fox would have been looking for extra work like this much past the 1910s.