There is some question as to whether this was the initial 1952 construction or the later second-deck expansion. Here's the photo by itself:
I don't know enough about construction techniques to speak with any authority. It looks as though they are installing the seats, which would solidly place this photo in 1952/early 1953. We do know that by January of 1953 the stadium was almost ready for the Brewers to move in. But is is possible that they are removing the seats to clear the way for a new addition? Did they have to do that, or could they build around them?
Interestingly, that corner of the double-decker grandstand is the same part of County Stadium later chosen for inclusion in the glut of local symbols that is Milwaukee's city flag.
But more on that next week....
UPDATE: Mystery solved:
@BorchertField This picture was taken in the spring of 1954 as additional seating was being built along the 1st base line.— Milwaukee Brewers (@Brewers) November 17, 2015