Wasn't it just double harmonics and left-hand pizzicato?
Didn't double harmonics mean that the bow was floating on the surface of the strings instead of pressing down on them? The positions for the correct notes had to be precise to ensure that the notes were in tune and there was sufficient control over the string vibration.
As for the left-hand pizzicato technique, it was more difficult than double harmonics. However, anyone who knew a little bit about the violin knew of this technique.
Did she have to take so much pride in knowing those terms?
The key reasons why Qin Ran said that was not these, but because Qin Yu was not proficient in double harmonics and left-hand string pizzicato. Her double harmonics were very stiff and sometimes, she went out of tune. The way her left hand pressed on the strings was quite sluggish sometimes and it made the vibrato very choppy.