This photo is of a real-life CIA safe house run in Virginia. It was used to house Russian defectors, to keep them safe from GRU assassins. In the Penumbra Database spy thriller, the CIA operates 8 safe houses in Key West, one houses satellite image interpreters, who masquerade as drywallers and drive a van with a "KW Drywall" logo! A safe house is used often in Hollywood spy movies, and is a secret place that's suitable to hide persons from foreign intelligence, like Russia's GRU.
You may find this declassified article interesting about how CIA safe houses are actually run: Behind the doors of a CIA safe house.
In foreign countries, a safe house has the main function of allowing clandestine meetings between case officers and their agents (recruits), in addition to serving as a refuge for defectors and people being pursued. I enjoyed the movie Safe House, but the gadgets and equipment installed in the place was a bit much.
Robert Morton is a member of the Association of Former Intelligence Officers and authors the Corey Pearson- CIA spymaster spy thriller series.