Some manufacturer's designed their early fielders gloves with a two piece face.
I didn't understand the advantage of that design over the diverted thumb models that were the norm at the time. I found a 1895 Victor ad that described their thinking. The ability to form a deeper pocket was the primary motivation.
Victor was one of the few manufacturer's to offer the gloves with the mitt pattern as well as some with diverted thumb seams or as Victor called it, the "straight thumb pattern". The 1905 Victor catalog page below features an equal number of both styles.
Two Victor gloves with the mitt pattern thumb seam are shown below.