In general terms —between masons — a thinner mortar joint is a sign of higher quality work, but require higher labor and skill. In comparable terms, mortar is cheaper than the masonry unit. So sloppy wide mortar joints are cheap, while thin and neat mortar joints are expensive.
In Capitol Hill, the front façades are often a higher-quality, more evenly-sized and shaped pressed brick, while the sides and rear façades are of a less-consistent, less expensive common brick.
Common brick with thick and sloppy mortar joint.
Pressed brick with thin and neat mortar joint
The brick on the right is the brick at the side of the building. The brick on the left is the face brick, made of pressed brick. You can see there is a Tidewater joint in the pressed brick; at the right (in the common brick), there is a much wider mortar joint.
GL Barnhart Construction ...The Blog 