50 ohm output impedance
The output impedance of an emitter (or source) follower is not the load resistor, as it would (approximately) be in a common emitter circuit. In fact, it is much lower- roughly the impedance the base sees divided by (hfe + 1), in parallel with the load resistor.

To see this intuitively, think of the large signal case with 10V on the collector, a stiff 5.6V on the base, and 470 ohm load. The emitter voltage is 5.0V. Now put a 470 ohm load on the emitter to ground- does the voltage drop to 2.5V as would be expected with a 470 ohm output impedance? No, it hardly drops at all- which tells you the impedance is very low.

Naturally, there must be a series capacitor or the DC emitter bias will cause problem with the input transformer or whatever it is connected to, but that's true with or without the 50 ohm resistor.