This postcard is the standard height of 3½ inches but is double width—11 inches. It was meant to be folded in half before mailing. Although unusual and uncommon, this size is usually ignored by postcard collectors.
When examining this card, I was intrigued by the fine print on the sides of the buildings. The buildings are named Wheeler & Wilson Sewing Machines, not Singer. Wheeler and Wilson was founded in 1851 and moved in 1856 to Bridgeport, Connecticut. In the 1850s and 1860s Wheeler and Wilson sewing machines were the most popular. Eventually Singer sewing machines became more popular, and Singer bought out Wheeler and Wilson in 1905. Singer company history dates the opening of their Bridgeport factory as 1907.
An interesting account of early sewing machine manufacturing history is found on the International Sewing Machine Collectors' Society (ISMACS) website. There is reproduced information and pictures from a 1873 tour of the Wheeler and Wilson Sewing Machine factory by a reporter. At that time the factory employed 6,000-7,000 in various capacities. The pictures are excellent views of workers at work with the manufacturing machines used at different stages of the manufacturing process.