It appears as an office building which has offices for GoPostal, Gruppe Sechs and the San Andreas Economic Recovery Group, according to the front signage. Despite this, only the former two are mentioned on and around the building itself.
A random car may pull away from the building on Vespucci Boulevard between 07:00 am and 15:00 pm, and another may pull in outside the building on Peaceful Street between 18:00 pm and 23:00 pm. A Bus may sometimes pull away from the bus stop just outside the building on Peaceful Street between 07:00 am and 11:00 am.
In GTA V, the building itself cannot be entered and plays no role in the story whatsoever.
In Grand Theft Auto Online, the building can be entered during the mission Heist Prep: Unmarked Weapons, either from the ground or through a rooftop entrance. During this mission, it shares the interior of the 'Executive Rich' style office.
Grand Theft Auto Online
The Cayo Perico Heist
WORLD_VEHICLE_ATTRACTOR: : 07:00 - 15:00 X:-218.807 Y:-869.8824 Z:28.8563
WORLD_VEHICLE_ATTRACTOR: : 18:00 - 23:00 X:-269.625 Y:-816.1886 Z:30.86011
WORLD_VEHICLE_DRIVE_PASSENGERS: CITY_BUS: 07:00 - 11:00 X:-271.8406 Y:-825.1581 Z:30.72715