Emitter follower with extra load in emitter path
The Q1 and Q2 circuits act as current amplifiers. Col A/B pins drive through a current sensing resistor on-board the chip to power ground. The addition of the emitter resistor couples the "load" current back to the base and thereby back to the sensing resistor. Without it, the current sensing part would not function.

The RC after the amplifier are to dampen  the higher frequency components of the switching.