The soft organic lines of modern Mercedes cars and the GLB concept have clearly made it to production, as there doesn't appear to be a single crease or sharp line on the car. It still has a very upright and boxy design, too. In fact, this is probably the boxiest Mercedes this side of a G-Class. The plastic fender flares do seem less exaggerated on this production car than on the concept. From what we can see of the bumpers, they aren't quite as chunky, either. But overall, it's faithful to the concept.
The GLB-Class appears to be based on the same architecture as the A-Class cars, as well as the upcoming GLA-Class successor. The concept suggests it will offer the slightly more powerful version of the 2.0-liter turbocharged 4-cylinder from the CLA, which produces 221 horsepower and 258 pound-feet of torque. That engine will probably be coupled with a seven-speed dual-clutch transmission and at least all-wheel drive. Front-wheel drive seems likely to be offered as well. There also appear to be AMG 35 and AMG 45 versions in development. The former will likely make about 300 horsepower, and the latter could make between 380 and 420 horsepower. An electric model has been confirmed to be coming, too.