Xue Sheng, since you have studied the other arts you should know both pre-natal and post- natal breathing. Practice the section with both types of breathing and you will discover the answer you are seeking.
Also keep in mind Yip Man changed the section to one hand at a time. Older versions of wing chun both hands are done at same time on the sides. practice both. Again the breathing will tell you the difference.
Also keep in mind Yip Man changed the section to one hand at a time. Older versions of wing chun both hands are done at same time on the sides. practice both. Again the breathing will tell you the difference.