The flag of Shanghai Municipal Council, Shanghai International SettlementThe flags are:

Top left: United Kingdom, United States, France, Prussia (for Germany).
Top right: Russia, Denmark, Italy, Portugal.
Bottom: Norway and Sweden (vertical and upside down), Austria, Spain, Netherlands (upside down).The text is:

工部局 (Municipal Council)
Omnia Juncta In Uno (All Joined in One)
Shanghai MunicipalityComment on the German flag:

FOTW says this was a slightly different version of the flag with a German flag which looks like Flagge Preußen (1892-1918).png.
Made by Ericmetro and others, using the description and image here and the following flags from Commons:

Swedish norwegian union flag.svg,
Flag of the Netherlands.svg,
BandMercante1785.svg,
Flag of Austria.svg,
Flag of France.svg,
Flag of the United Kingdom.svg,
Flag of the United States.svg,
Flag of Denmark.svg,
Flag Portugal (1830).svg,
Flag of Italy (1861-1946).svg,
Flag of Russia.svg,
Naval Ensign of Russia.svg
Ericmetro and others