At first, I thought this was a photograph of Central Market.
ebay
but the seller places it at 3rd Street and Central Avenue.
United States Post Office
Arcade Annex
3rd & Central puts it just north of the Arcade Depot.
www.bigmapblog.com
After a quick google search or two I found the Arcade Annex Post Office was only open from 1930 to 1940.
I also came across these letters postmarked from the Arcade annex.
http://www.postalhistory.com/results...E&searchtype=2
http://www.postalhistory.com/results...E&searchtype=2
I'm including this one because of the dog.
http://www.postalhistory.com/results...E&searchtype=2
__