Hi Hokwang Lee,
Yes if you check the Pipeline Syntax snippet generator that checkbox controls incremental (true):
This is described in:
Polling per Change: A build is carried out for every change that is submitted. The polling event will only return the oldest
unbuilt change, resulting in incremental builds.
Therefore when enabled you should see:
CL 1 submitted.
5 minute poll builds CL1
5 minute poll builds CL2
5 minute poll builds CL3
As you can see for every change to be built the polling has to occur more frequently than the submits.
If you really want on demand builds for every changelist a 'change-submit' Perforce trigger that explicitly calls the Jenkins job URL passing the changelist as a parameter is the recommended mechanism.