behavior of expand icons[+] in Pivot table

Hi all,
I want to make sure the behavior of expand icons[+] in Pivot table
BIP:11.1.1.6.6

There are two behaviors:

1. If subtotal line/subtotal row is set in pivot table,
  the outputted report has expand icons[+] in interactive mode automatically.
  And I need to click all the expand icons[+] to see the whole contents.

2. If subtotal line/subtotal row is NOT set in pivot table,
  the outputted report doesn't have expand icons[+] in interactive mode.

Is this an expected behavior?
If so, is there a way to control(set or unset) the expand icons[+] by any setting in pivot table?