My interpretations:
Guo vs Li - circular plane of sword energy traveling along with Guo's sword. Imagine sticking the sword into the middle of a big circular piece of cardboard. Then do a thrust with the sword, the cardboard represents the chi (according to my imagination). It covers an area, so Li can't easily dodge, but when Li hits the sword energy is knocked off too.
Chongxu: I imagine these as being unfilled circles, as opposed to Guo's filled circle.
H7G: I imagine this as just being one big blast of wind. Because it's not connected to Guo, and is filled, it is not possible to get past it easily.