Hey there,
Yes, this setting will allow site blogger have the permission to select which theme they want to use it, so this user selected that theme from their blog user profile, it will show on his blogger page.
You can follow my below step to achieve this :
#1. Go to backend > Easyblog > settings > layout > general > MultiBlogger Themes > select themes > save
#2. Need to use single author menu item with enabled `standalone mode` options (Mean create single author menu item for which site user want to use this)
#3. Then go to frontend choose the theme from edit blog user profile (Currently is not possible select the theme from Easysocial user profile), unless you disable this option "Use EasySocial Edit Profile Link" from backend > Easyblog > settings > integration > Easysocial
Hope this help.