A reader who is genealogically-equipped supplied me with some interesting details, to wit:

"Since I am originally from the Boston area and a genealogist (access to various databases), and I love a good mystery, I thought I would take a stab at it.

Here is my take on the picture.

1.  Sign on door says "Floors to Let Wm Pease O'Brien".  William Pease O'Brien appears to have been a well-established realtor in the Boston area during the time period in question.

2.  The 1947 Boston City Directory shows Williams Mfg. Co. located at 70 Beach Street in the Simon Building.

3.  The 1955 Boston City Directory show Julius & Sons also located at 31 Beach Street.  

4.  Beach Street is in Chinatown. In fact, it appears to be the center of Chinatown.

5.  The 1947 Boston City Directory shows the Cathay House Restaurant located at 72 Beach Street.

If you look to the far right of the picture, you might imagine a Chinese restaurant.  A paper screen/shade in the window, a quasi-chinese hanging lantern, maybe a green awning that is rolled up, and some out of place tile design on the wall.

End result - I think everyone when out for Chinese food on New Year's Eve.

Here's a photo of the Cathay House in Boston, and here's a postcard.

It seems like it was quite the place at one time. Well, at least for 1940s - 1950s Boston Chinatown.

Hope I didn't crush any dreams with my thoughts on the picture."

No, not at all! Mystery solved, thank you!

Google maps streetview shows 70 Beach Street today; not all ALL as noirish and as evocative as it was!

From a website about the Boston Tongs:

"The Boston Tongs, like most Chinese in America, were in both the laundry and restaurant businesses. Harry, William, and William’s nephew Tommy, and Doo-Park and occasionally I were working in the Charlie Mun Hand Laundry until well into the 1960’s, while Herbert and Albert had long switched to the chop suey endeavors. Albert became the co-manager of the Cathay House, which for many years was the No. 1 joint in Chinatown, due primarily to high management standards laid down by Albert. For example, before the opening hour of 3:00 p.m., all waiters and headwaiters had to line up for dress and fingernail inspection, while none of the other restaurants had this kind of institution. As a result, their evening dinner line, especially on Fridays and Saturdays, was frequently an hour long. Herbert was working as a waiter there and in the 1950’s his monthly pay was well over $300 while the average was somewhere around $200. The Cathay House was a first-class eating establishment in Boston. In the late 1960’s, however, a rumor started in Italian North End that Cathay was caught by the City Health Department for putting cat meat in the chop suey, just at the time when the huge neon sign out front went out of order and the lower half of the sign (the “H A Y” in CatHAY) went out. Business was never the same afterwards and the restaurant was finally sold. Competitors would laugh at the place as being a house of prostitution. The saving feature was that President Nixon in 1972, bless his soul, “introduced” real Chinese food into this country and suddenly there were Hunan, Sichuan, Shanghai, and Beijing cuisines, and the Chinese restaurant business had its renaissance, delicious indeed. The old Cathay became a tea house, business bloomed once again."