The Sonn Brothers, Henry and Hyman, first went into business in the 1870s as grocers, but by the 1890s they were liquor dealers and operated from many downtown locations. Their offices were at 440 Washington/31 Desbrosses from 1901 to 1912, and this faded sign advertises that location.
Surprisingly, Walter Grutchfield has gleaned quite a bit about the Sonn family, which originated in Germany, and their business activities over the years.