Outdoor eating is rightly believed to enliven a street. Being outside can also make eating more fun for patrons. Miami has a number of eating establishments that take advantage of very small spaces with a variation on a sidewalk cafe. This variation is serving people using a pass-through or having people eat at a counter where the food preparation is done inside and the customer eats outside.
An excellent example is La Sandwicherie, on 14th Street and Collins Court (effectively, an alley that runs parallel to Collins and Washington avenues) in Miami Beach. La Sandwicherie is less than 10 feet deep (see bottom photo of its short side), which includes work space, storage, and a passageway. Patrons sit on stools or stand at the counter, under the protection (if necessary) of an awning (see middle photo).
"Yes, Andrew, this is very nice for a warm climate like Miami's". Yes, Miami's weather (short of the hurricanes) is conducive for this type of restaurant design. However, there is ample evidence that people are willing to eat outdoors in much cooler weather. Just look at the success of cafes in Paris during non-summer months. Find a busy crevice in a temperate climate where people are hungry, and this type of design might work for most of the year.