Zener resistor configuration
You are mixing up a couple of concepts. The zener dynamic resistance is the change in zener voltage divided by the change in zener current around an operating point. It's a linearized portion of the I-V curve. 

The zener voltage vs. current curve is nonlinear and generally pretty miserably non-ideal for a 3.3V zener.  Below is a typical set of curves from another answer:



You can see that at 10mA you get around 3.4V from the "3.3V" zener but at 0.1mA you get more like 1.9V. It's not easy to see the dynamic resistance on that set of curves because it's a log-linear graph, but the dynamic resistance will be much less at high current. It would be the reciprocal of the slope of the curve on a similar but linear-linear graph.  

Higher voltage 'zener' diodes behave in a much more ideal fashion, with almost vertical I-V curves over a wide range of currents. So mostly we avoid use of low voltage zener diodes in favor of active circuits such as the TL431.