One of the three shops was empty at the time that Nick and Tom walked by the brick building in which the three business spaces were located. The second of the businesses "was an all-night restaurant." The third of the shops was George Wilson's business location and, upstairs, the residence for George and Myrtle.
Upon first entering the garage, Nick is underwhelmed by the appearance of the surroundings. "It had occurred to me that this shadow of a garage must be a blind, and that sumptuous and romantic apartments were concealed overhead..." He soon learns that what he was seeing was the reality of the business - it was a gray and lifeless as everything else in the valley of ashes.
In Chapter Two, Nick accompanies Tom to the Valley of the Ashes. According to his description, this area contains only three shops in a sort of compacted version of a typical "Main Street." The first of these three shops is completely empty and is available for rent, the second is an all-night restaurant, and the third shop is a garage. This garage is run by George B. Wilson and advertises itself as a repairs shop where cars are also "bought and sold."
These three shops exist in the middle of the Valley of the Ashes, a sort of wasteland in between West Egg and New York. It is a miserable, gray place, constantly surveyed by the eyes of Doctor J. T. Eckleburg. It is also significant because it is home to Myrtle Wilson, who longs to escape the desolation of the Valley and enjoy a life of luxury with Tom in New York.