学习TechAnalysis Of The_Financial Markets的一个疑问

scdog

持续形态讲对称三角形的时候，提到的volume的重要性，有两句:
but the volume should pick up noticeably at the penetration of the trendline that completes the pattern. the return move should be on light volume with heavier activity again as the trend resumes.

感觉怎么有点矛盾啊，求解。谢谢大家。