It’s an advertising pocket-piece given by a company to prospective customers.
“The Man With The Gunn” is a play on words, since the company concerned was the Gunn Furniture Company of Grand Rapids. The company was the successor to the Gunn Folding Bed Company established in 1890 and they changed their name in 1893 after folding beds declined in popularity. From then they produced roll-top desks, sectional bookcases, letter filing pigeon-hole devices, and similar goods in numerous styles. I have two of their glass-fronted sectional bookcases but use them for displaying china.
The ‘token’ simply boasts their achievement in being awarded a gold medal at the 1904 St Louis Exposition (a major World Fair where manufacturers could showcase their products) and was given away for some years after that.