In this case I am going to venture out and guess he is talking about the PPS being at the apex of the triangle as shown on his chart: Of course Cappy has to confirm that as I may be off on my thinking. (Post continued after chart....)
To me a pinch is where the PPO and ADX line come together as seen in the top two boxes and referring to the green line and the white line coming close then spreading apart (See around Sept 9th for the spread).
Also a Bollie can tighten or pinch as well. Which is technically happening on the chart as we speak (Bright pink lines).
And then there's the irritating thing a brother does to his sister to make her cry. ;)