Bonus room -- unpermitted or not?

[Bienes Raices]

My offer is in & accepted on an REO...

Botht the MLS & county appraiser site says it's a 3 bedroom, but there is large extra room on the front right side of the house.

Naturally I thought that it was an unpermitted garage conversion. But the exterior of the house is completely uniform -- painted cement block where you can see the outline of the blocks -- instead of the typical conversion where there is wood or some other type of material around part of where the garage used to be, that doesn't match the rest of the house. In addition, the other houses on the block (same architectural style) don't have garages either, which leads me to believe that it was never a garage.

Does that mean that someone added an extra non-load bearing wall inside the house to divide the living room & create an extra room? Or is it possible that the county made a mistake and forgot to include this room in their records? There are no closets in the room. I don't know if this should be an issue of concern to me or not.