The CTD (Smyk) Department Store was built in 1948-1952 and designed by Zbigniew Ihnatowicz and George Romanski on Aleje Jerozolimskie.  It was built in the Modernist style of the pre-1920s and was an outstanding example of this kind, certainly in Warsaw, in its day.  Today, unfortunately, you would hardly notice it, unless you were an architecture buff that is.  It is draped in the over-the-top Smyk advertisement (see picture below) and is also in need of a renovation.

According to wikipedia, the building is going to be renovated and redeveloped.  Here's hoping the future looks bright...

Read the full article here http://en.wikipedia.org/wiki/CDT_%27Smyk%27_Department_Store

Here's a photo of the building at night: