From that first sign came signs featuring tankards of ale for Middle-ages inns, signs with a shoe for those who made and repaired footgear, the anvil and hammer of Colonial America's blacksmith's signs and the eskimo in the photo above.
It was not until universal literacy became a fact that words replaced this kind of direct reference symbol in signs. As late as the early 20th Century in America, the picture was the dominant element in business signing. Public education changed that. When you see that sort of thing, today, it is normally the result of tradition -- unless the corporate logo is so well-branded that you don't even need to name the company. Who made this pair of shoes?