As it says Detskoe on the back and refers to the Alexander Palace Museum, the card must have been printed after the Revolution and I would say in the 1920's. Detskoe Selo (Childrens Village) was renamed Pushkin in 1937. Now the town is back to its original name Tsarskoe Selo but one can use any of the three names, they all mean the same place. Any of those names are understood and recognised.
Alan